The only way to remove all uncertainty is to test the iron level. Any amount that your test kit can detect is enough. Anything over .5PPM should be avoided due to the potential for kidney damage (of the fish) if the level is over that amount for a long time.

In actual practice you can just watch the hyacinths and add some iron when they seem a little punky. Chlorosis is pretty easy to recognize after you have seen it. I add an ounce or two to 2,500 gallons of water. It doesn't take much. I typically will add my micro-nutrient mix three or four times a season.

It is really easy to test for nitrates. Mardel makes a good 5-in-one test strip that includes nitrate. I shoot for 10-20 PPM. There are other manufacturers that make crappy test strips, like Jungle, so try to get the Mardel strips if you can. Do read the directions.

Potash is needed in greater amounts than nitrates, so I usually add potassium chloride in an amount equal to the potassium nitrate I add. It is much harder to test for potassium, but even great excesses of potassium (potash) are not a problem.

I have Tetratest strips, and if that is a decent brand, then everything tests normal. Water is a little hard.

Remind me which form of potassium the stump remover is?

I hope the hyacinths will be happy. They are not "laying down" for a few days, as the guy who sold them to me said they might. One or two are BLOOMING, something I never saw before in the tiny store-bought ones I had.

I love ponding, even if I only understand an 1/8th of it so far. :)

What was the iron level before iron was added?

Another way to test for a missing nutrient is place a few plants into a separate container with pond water. Wait a week, they may improve just by being on their own. If no improvement add the nutrient and see what happens. Should see results pretty fast.

In a pond with plants and fish where you're adding fish food all the time, plus water being added depending on what's in that, nutrients would not be on my list of concerns.

Add every thing you can think of and you will have issues.

Stump remover is potassium nitrate. It should say so on the packaging.

All water is not equal. Water contains a highly variable mix of minerals. Tap water and well water are very different, and water varies from region to region. Some water contains potassium in sufficient quantities, some does not. Some water contains nitrates, some does not. Same for phosphates, iron, boron, magnesium, calcium, and sodium.

If you are lucky enough to have water that contains the right mix of potassium, nitrates, and iron, but that has no phosphates, you likely will have no need to add anything but more water. If the above is not true, then you are going to have to pay attention so you can figure out what you might need to add to your pond to keep your floating plants healthy. Water is intended for drinking and washing, they don't formulate it for the benefit of pond plants. That is up to you.

Thanks, Larry. Since the previous WHs all only degenerated and died, NO signs of growth or "plant happiness," I certainly hope that adding the iron did not hurt but might help. I've been doing the stump remover for a couple of months.

Boy, you guys are gutsy! I would no more add iron or stump remover to my water than fly!!! I am absolutely NOT a water quality specialist, but I have been ponding for years and learned long ago that everytime I add something foreign to my water, it takes months to recover and rebalance. So I stopped and now let nature do the work.

Pat, if what you have been doing is working you shouldn't add anything. Adding iron only works if your plants are iron deficient. If it ain't broke....

On the other hand, if it is broke you need to fix it. There is nothing quite as good as adding iron to cure an iron deficiency. If your hyacinths all turn sickly yellow and die your pond is likely deficient in iron.

I have had good luck with the adding stump remover (Gordon's: brand) too.

But Larry & friends, one thing though that Drh1 taught me about the right use of stump remover: most of the potassium nitrate stump removers won't say it on the label. You have to ask for the material safety data sheet (MSDS) on the product or visit their website or something. This is because the material while not volatile, it has been used in bomb-making... so they don't like to circulate that word too much -- good thing.

And I've found that in my neck of the woods most of the brands that do publish/print on the label the compounds, well, they are not the potassium nitrate-based stump removers that we're looking for. Bonide is one brand that is not to be used in ponds.

Just FYI to everyone.

Yellow leaves may be a lack of iron. But "likely"? Lots of diseases will keep a plant from using iron properly. High pH can make iron uptake impossible for some plants. Lots of other things that will turn leaves yellow. And its not just "yellow", iron chlorosis is not real easy to diagnose.

I sure wouldn't dump iron or any other chemical into a pond based on "yellow leaves". Who doesn't have some yellow leaves? People without a lot of experience are going to a see a yellow leaf and start pouring stuff into their ponds. I mean no big deal, easy enough to drain a pond, replace all the fish and start over. Way easier than testing the level in the first place.

And people have problems with their ponds? Go figure.

OK, I will leave my pond water alone!!

Gosh, I do love all of your different advice, but it's hard for a brand new ponder to figure out what is what. :)

I did add iron and stump remover but now I will let things be for a while.

One thing I really like now is the smell of the pond. It smells "right." Don't ask me what that means, but it does. You can't smell anything until you do something in the water, but then it just smells like nature in a very good fresh way.

It is actually impossible for a new ponder to figure out this stuff because there is an endless amount of info, good, bad, partly true, completely insane. And then a bunch of interactions when something is true in one case and not another.

If you ask a question you will get every possible answer, myth, fact, misunderstood. It is absolutely impossible for a new ponder to separate good from bad because of no experience.

Books are also full of every myth out there. Water gardening has never been a science. Fish hatcheries, Koi ponds and sewage treatment have data, not water gardening.

The bottom line is you have to learn for yourself. Pick an opinion and try it...but remain skeptical. Test results with scientific analysis. If you find something wasn't true, figure how where you were mislead. In a year you'll know more than 99% of ponders.

You will almost never find any advice here that is backed with any testing at all. Only anecdotal evidence and misleading logic.

I could fill a book on the myths I've fallen for over the years.

When I first started water gardening this chat and others were flooded with warnings on the dangers of concrete in a pond. No descention, 100% agreement if you put an ounce in a pond the pH would shoot high and kill all your fish. It got so bad people were warning concrete shouldn't even be near the pond because rain run off would kill the fish. Many of the people I still see posting here held that opinion and shared it every time someone mentioned concrete. Every discussion that contained the word concrete devolved into the same "you'll kill your" pond.

They had people dumping acid into their pond, redoing ponds, and actually killing fish with all the "fixes" to solve a non-problem.

I've been away from pond chats for several years. I don't know, maybe this opinion is still common, but I haven't read any in the past couple weeks.

That myth was so easy to test, just a simple pH test. Only when I was forced to add a couple concrete blocks and tested pH did I wake up. I've testing stuff every since.

The concrete myth was super easy to prove ridiculous. But for more than a year I argued the point in this chat and others. I did many experiments adding more and more concrete and gathered test data. But the "experts" stuck to their guns. Over time they just kind of pushed the concrete myth less. Never once did any "expert" test the theory for themselves. Some of those "experts" are still here.

Most other myths are a bit harder to prove so it's completely pointless to argued the point here with "expert". In chats, doesn't matter the subject, it is far more important to appear right than be right. Anyone can be an "expert" here. When a new ponder gets burned they just disappear from the chats.

And new ponders is why I even bothered to push the point at all. A vast majority of new ponders quit within a year or two because of all the insane advice they got. And that I always thought a crime. I felt and still do that a pond can be a huge benefit to wildlife. But "experts" don't care about ponds, they care about appearing as an expert.

Here's my "expert" advice:

1. Go slow. If you make 2 changes to your pond how are you going to know what did what? Start with a low fish load, a few goldfish.

2. Test whatever you can. See how your pond changes over time. Don't assume something is good or bad. Test it. If you can't prove it, don't do it. If something works sometimes and not others it probably never worked at all. When you do something expecting to get certain results and then those results happen it doesn't mean what you did caused the result. Instead of patting yourself on the back do more tests.

3. The one thing I have found useful is baking soda. Research it and see if it makes sense to you. Test for buffering level and pH testing is hardly needed.

4. Have confidence in nature. The bacteria, insects, algae and fish have been doing this water garden thing for a lot longer than you or anyone else. Let them teach you. Then you can start messing it up and learning more.

5. Adding city water is the same as adding chemicals. Test and deal with issues.

6. Clean the pond as you like or don't. This is only an aesthetic issue. Check out the ponds where goldfish and Koi are raised to see what conditions they actually like. It isn't a clean pond.

Most notably missing from my list are filters and pumps.

Water movement is nice but not needed. How does O2 get into the water? The surface, no movement needed.

Bio filters are a compete waste. But check it out for yourself, how does bacteria grow and where? Doesn't it occur throughout your pond? Doesn't fish load affect bio filter needs?

How is waste broken down? If something "removes" it, where does it go? Or is it still inside the pond in another form? How much waste is produced vs the amount is actually broken down?

Sorry for the long post, this will be my last for a few more years.

I use stump remover and/or "iron" whenever I feel I need to. Having gardened for over 40 years as well as "water gardened" for over a decade plus a bit of "experience" in water chemistry-related stuff I usually hope that I know what I'm doing. The chemical addition calculator that I've posted in the past was/is designed to allow you to add certain things without destroying anything. Unfortunately many folks operate under the principle: if a little bit is good more is better!!!!! Plus there is this terrible sense of urgency about life that makes them want instant results!!! Oh well. One comment about adding iron: bio-availability is pH dependent, as mentioned above. However, you can mitigate that quite a bit by using chelated iron (it will say so on the container). This isn't the same as putting a rusty nail or screw into your pond or pouring in iron sulfate. Also note that many forms of liquid iron may have small amounts of copper in the solution. While trace amounts of copper, zinc and iron are good for many plants excess will kill them rapidly. Just proceed cautiously if you decide to add something. Also make sure it is well dispersed in your pond as soon as possible (which is why I add mine at the inlet to the skimmer...it gets diluted and dispersed better than if I attempt to disperse it by hand). Just a few thoughts.
---David

Thanks, David. I did add both (I got the iron from a fish place so I assume it was safe but don't know if it was chelated).

Water bug guy, why would this be your last post in years? You should stick around.

I agree with you about changing things one at a time and following the scientific method as best we can.

I disagree with you about biofilters being worthless, and not because I spent a ton on it. I had a pool-to-pond all spring and part of the summer with NO filtration or aeration.

The first few days once we got the filter and pump working, our entire yard smelled GHASTLY. You could even smell it in the house. I fear our neighbors were also smelling it. The smell lessened on the 4th day, and for a week you could only smell it badly near the filter itself, or the water pouring back into the pond.

When the guy came after a few weeks and cleaned the filter, it was filthy and smelly. Pee-yew!

However, since then, and even the 2nd filter cleaning, the pond does not smell bad. Only scooping the VERY BOTTOM (around 7-8 feet down) will get a scooper that has a faint poor smell. The whole rest of the pond smells pleasant. The movement of the water is NOT only at the surface. It smells good all over the shallow end of the pond (3-4 feet). That is proof that it's no longer anaerobic as it was, with that ghastly "pourri" smell.

David, I think you hit the nail on the head. Imparting experience on new ponders is a dangerous game. No matter what you write many people will read "bah, bah, bah, iron, bah, bah, plants, bah bah, good". They run out and buy the first thing they see with iron, who knows what actually ends up it the pond. I just wish more advice came with a lot more disclaimers, testing requirements, measuring, etc... Iron is pretty safe stuff, but being sloppy is a bad path.

Hawk, I spend too much time in chats. It's just entertainment. I learned long ago it doesn't really help. But I enjoy talking about ponds...too much. So I'm hoping to stop and get back to work. Work is a bit boring right now, but seriously, this will be my last post for awhile. I also have to stay away from Freecell.

And to that point...bio filter and mechanical filter, two completely different filters.

A properly installed, sized and maintained mechanical filter can do its job of removing waste (that GHASTLY smelling stuff). I've seen these in Koi ponds. Water gardens, not so much.

A bio filter on the other hand only removes ammonia and nitrite, which have nothing whatever to do with that GHASTLY smelling stuff. In order for a bio filter to not be completely worthless there has to be some ammonia and nitrite. Measure the ammonia and nitrite in almost any water garden without a bio filter, or more commonly, a bio filter so clogged it stopped working years ago, and you'll measure none. Of course there is always some present, but there's a lot that wants to eat it before it can get to a bio filter. Plants (algae) will take up ammonia and ammonium directly plus you've got all that other bacteria living inside the pond.

A bio filter has to be sized to make up for the difference in waste produced and what the pond can handle. Total number of water gardeners who have done that calculation? I'd guess pretty small.

The completely odd thing is that ponders always guess exactly right on what size and type of bio filter their pond needs. I mean isn't that just totally amazing? Bio filters never seem to be too small. Of course the package on bought bio filters make it easy and tell you what size pond it handles because of course it has nothing to do with the number and size of fish in the pond, right?. It is all rather funny really.

Just as a side note, about the GHASTLY smell...aren't we kind of ignoring the fact that every single creature in your pond evolved in that exact environment? It isn't a perfect environment for fish of course, but they can deal and they like eating the bugs supported by all that muck. Now a dozen 20 lb Koi in a 1000 gal pond (tank), that's another matter and nothing to do with water gardening.

I like a clean pond and I'm all for removing muck for lots of reasons. But lets use our heads here. And certainly a bio filter has nothing to do with removing muck.

There's an hour I shouldn't have spent here. And what good did it do. 100% of ponders will continue to not care about the difference between a bio and a mechanical filter and only care that they built or brought that cool looking gizmo over there that is saving all the fish from certain death. Yea for us. Luckily it's one of the less harmless myths.

To put my toe in the "filter pond" or not...that was the question in my mind. Oh well, here goes a few "additional words" on the subject. But first, Hawkiefriend, I apologize in that we seem to have hijacked this thread from "iron" to "filters".

Many folks talk about "mechanical filters" and "bio-filters" and seem to indicate that they are two, totally unrelated items. In fact, they are varying shades of gray, if you will. There are a limited number of "forces" available to move "stuff" around in an aqueous environment. There is gravity...it works well on large things, things greater than say 20-30 microns in size. There is molecular diffusion...it works over very, very, very short distances generally in the sub-micron size range. An experiment that proves the point is to fill a glass with water exactly at room temperature and let it sit for several hours undisturbed but covered with plastic wrap. Using a hypodermic needle slowly add a solution of sodium chloride and water (yes, there will be density differences) to the BOTTOM of the glass of water so that you dont mix it. Keep the glass covered with plastic wrap to eliminate evaporation and evaporative cooling. It will take DAYS for the salt to make itÂs way to the top of the glass if youÂve done it right (no mixing). True molecular diffusion is a very slow process over what seems to be a short distance. Then there is what is sometimes termed eddy diffusion...the "eddy" can be as large as the Gulf stream - you may have seen photos from space - or as small as something similar to you swirling a spoon through your coffee cup (or even somewhat smaller). The small eddy diffusion phenomena is probably the major factor for "moving" dissolved stuff over to a surface where and organism can then ingest and convert it. The final "force" could be called interception...the "stuff" is too large to pass by an object...an example being a leaf collected on a screen. There are a few other forces at work but these are the main ones. Why mention this? Because these forces are working all the time. They do not shut down at night. They are impacted by temperature, wind-induced currents, a fish swimming by, etc. but the above factors act all the time.

A so-called mechanical filter is usually "designed" such that it uses interception and/or gravity to remove "stuff". Examples: the mechanical screen you have in front of your pumps (interception); some of the more advanced "settling chambers" currently used by various Koi enthusiasts or the bottom drain in your pond (gravity). But that doesnÂt mean that diffusion isnÂt taking place ... it does, but the time for it to act and the distances involved are too great for it to have much of an impact on removing such "stuff" as dissolved organics, ammonia, etc. Likewise a bio-filter which relies predominately on diffusion and eddy diffusion to move "stuff" dispersed in the water to where it can be adsorbed (activated carbon for example) or where it can be converted (a bacterial film on a plastic scrubbie) also has interception and settling take place. So-called bio-filters typically have significant sedimentation taking place within the tank since the velocities are reduced to provide the contact time for molecular and eddy diffusion to move the "stuff" from the water to that scrubbie where a variety of organisms are growing. Not only is there direct sedimentation (silt, sand, etc.) entering the unit but also there is what I might call "indirect" sedimentation. As the organisms convert the "stuff" that has been brought to their dinner table what do they do with it? They grow, multiply, etc. to the point where "chunks" of biomatter break off and settle out to the bottom of your scrubber. If you get too much biomatter growing too rapidly in your scrubber (meaning it is undersized for the fish and food loading and temperature you are working with, plus the necessary velocities to move the "chunks" out of the unit) you get what is technically called channeling - no, Horton, this is not about having a seance with Aunt Matilda! - where you have higher velocities carrying out some of the "chunks" which, of course, then settle in your pond. So I guess I donÂt see that there is really a big difference between a so-called "bio-filter" and a so-called "mechanical filter". The same forces are evident but the residence times within the units are significantly different allowing one set of forces to be more effective in moving stuff around. This is just a different way of looking at the process without getting too hung up on the terminology.

One last comment...youÂll note that I put " " around the word design above. From what IÂve seen in the Koi literature as well as the small amount in water gardening thereÂs very little true design involved. A great deal of experimental work (in some cases)...yes, but a great deal of very subjective conjecture, hype and advertising in others. If youÂre happy with what you have and itÂs meeting your expectations donÂt worry about whether itÂs mechanical, biological or due to the phase of the moon. Sit back and enjoy it instead. Thou shall not covet thy neighborÂs bio-filter! LOL!
ÂDavid

Great post Prof.
You are definitely getting better, I only fell asleep twice reading that one!
I'm pulling your chain, it really was very interesting.
I'm just giving an example of "interception" and about "stuff" being to big to pass through! Maybe that should have read "conception"! LOL
By the way, Aunt Matilda sends her regards, says it is very hot down there, but she is sure you'll get used to it! ;-)
"Horton"

Resident "experts" hate any kind discussion. They prefer to belittle and bash in the hopes they get their little kingdoms back.

Because I am a new ponder I am not sure if there is some sarcasm going on here or why.

I don't mind the thread hijack.

I really want to learn about filtration. I know that in all the koi literature they talk about REAL filtration (mechanical) and they know NOTHING about bio-filtration. That is why my pond guy scrubbed and washed all my bio media with hose water.

So many people have used a bio filter in the proper size and had the water in their pond become clean.

Mine has still not. It's been a good month or so since we have scrubbed down the whole pond, and things have definitely changed, as water bug guy said they would. The thick, bubbly green goo left and was replaced by a thin fuzz on the surface of the water. Then we got tons more plants and the fuzz left and the surface of the water is perfectly clear.

However, the water appears dark and we can't see even the top step of the ex-pool.

The mosquito fish, and I presume any of the goldfish or tadpoles in there, are probably happy. I'd just like to see them. I'd love to have a couple of feet depth of visibility.

Trying to be patient.

Hawkeyefriend,I Guess that last post from waterbug-guy was directed at myself and it is away of course.

I can assure you that there as no sarcasm meant at all in my post to David or anyone else for that matter. My remarks were to David alone. We have been friends for years, on and off this forum and tease back and forth with each other frequently, it is just a bit of fun between us.
There was nothing sinister in my comments toward anyone else.

In fact I thought both Waterbug_guy and David had some interesting points about filtration and I was enjoying reading both of their inputs on the subject.

The dark colour of your pond water could be caused by tannins from decomposing tree leaves and plant matter or soil erosion entering the pond.
A bag of activated charcoal placed where the water can run through it may help in removing the tannins.

Wash the activated charcoal out, to remove the dust from it and place it in a mesh bag to allow the water to filter through it.
Hope this helps,
"Horton"

Hawkiefriend, I have no idea either as to what/who the comments were aimed at. Of course, I recognize Horton's target!!! LOL! Like he says, we've been friends over the years and we pick on each other but always in good fun (although not necessarily in the best of taste! LOL!!). Just ignore our banter and attempt to get the information that will be of help to you.

So, just to add another, different viewpoint on this whole thing of filtration: Suppose you had a water garden/pond around 800-1000 gallons (I suppose I should also convert this to liters so Horton will feel more comfortable with the units). If you had a liner in there and nothing else it would probably have approximately 150 square feet of surface area. Assuming no rocks in the pond and nothing else other than a few fish and water there will be a growth of organisms (algae, nitrifiers, etc.) on that surface since many of these grow best when attached to a surface (as opposed to suspended cultures). Over a period of time there will be a production of gunk/sludge/debris...what ever you want to call it. Now for the same pond add a filtration system, call it a bio-filter if you want...that's just some terminology that folks like to use. Say that this filter is a Skippy filter and contains media that presents another 500 square feet of surface area due to the filter pads, bio-ribbon or scrubbies present in the tub. Let the same amount of growth now occur but spread uniformly over all the surface. Result? In the system with the filtration roughly 77% of the debris will be produced there in the Skippy rather than in the pond. So now ask yourself which is easier to clean at the end of the year??
While it is true that whether or not one needs a filter is highly dependent on the fish load, the amount of food you feed them, temperature of the water, etc. I think for the average ponder it is appropriate to have a filter. I have yet to hear a single ponder claim...WOW my filter is too big!!! If you are going to have a single gold fish/comet in a 1000 gallon pond...forget it; save the $$$; save the electricity; save the maintenance time. But those little buggers seem to multiply (even when there's only one!!!!!LOL!) plus most folks seem to enjoy dropping a tidbit or three into the pond to watch them feed. I know that we do...we usually go through 20-30 pounds of "tidbits" each year!!!!! So for filters...this is one time where I think bigger is better!
---David

All the serious Koi owners I've know have had an excellent understanding of mechanical and bio filters. I learned what I know from Koi keeper and papers on sewage treatment. All filters I'm aware of used in water gardens came from the Koi industry. In the case of a "pond guy" who kills a bio filter the problem is either the pond guy not being a "pond guy" or the pond owner thinking they have a bio filter when they really have a mechanical filter. Given the discussion here I suspect the later.

Just to hammer the point to death...

It doesn't matter what the filter is called, or what material is inside or what the ponder intends the filter to do. It has to do with how it is used.

A bio filter by my definition is for growing bacteria. More surface area, more bacteria (assuming there's enough food for them) as David said. A "bio filter" that cogs (tons of muck comes out when cleaned) can't be called a bio filter. It's a box of muck with very little surface area remaining. A proper bio filter will be proceeded by one or more mechanical filters to keep the bio as clean as possible.

A mechanical filter traps debris. Cleaned weekly to prevent large matter from breaking down into tiny matter and overwhelming the bacteria capacity. If not cleaned often it is also just a box of muck. When a mechanical filter is cleaned correctly it doesn't smell very bad because not enough time has been given to allow for much breakdown.

You can tell when a mechanical filter is installed, sized and maintained correctly if the pond is spotless. If a mechanical filter is only removing 5%, 10% or even 50% of the debris when a ton of debris is generated I don't really see the point. The remaining debris is more than enough to cause all the same issues 100% of the debris would have caused other than build up over years.

I think it gets confusing when people say debris is removed in a bio filter. Of course it depends on the definition of debris. My definition is anything large enough to see with the naked eye that you don't want in the pond. I don't consider ammonia for example to be debris. I have never seen or heard of a pond or even a sewage treatment plant with bio filters large enough to completely break down all organic matter. It is certainly possible, but not practical. Much easier to remove 99% of debris with different mechanical filters and then the bacteria has a chance of removing most of the remaining.

If a ponder wants clear water most of the time they really have to get serious about removing debris, even more so than Koi keepers because a water garden will generally have have much higher loads.

To my way of thinking if I have to clean a filter once a year and also vacuum because the filter only removed some debris then it's easier for me just to vacuum. But every pond and ponder is different.

I'm a little too overwhelemd at the moment but am I undeerstanding this corrwect... you're adding Iron AND Stump Remover to a pond wuith fish because your water hyacinth died? That sounds insane to me.

I did, on advice from people here. I hope I didn't do anything wrong.

Whew! You guys wear me out! Here are a few practical suggestions that may help you determine what you want to do. First, determine what kind of pond you want: Are you supporting Koi or just a few goldies for fun and color? My understanding is that Koi require a bigger, deeper pond with better filtration and require more space per Koi so add fewer. Go to a good Koi site and read up on the needs and requirements so you feel comfortable caring for them. In contrast, caring for goldies is a simpler process and more forgiving. I still have many of the original goldies I put in my pond 15 years ago, and, trust me, I made alot of mistakes in the beginning!!!!. Second, purchase a good water testing kit and test your water periodically. Find out how to read each test and what it means to your pond. In the beginning, I was dumping all sorts of things into the ponds for the miracle cure that never came. Had no idea what worked and what didn't because I couldn't wait to find out before I tried something else! Begin to rely on your own senses. How does the pond look? smell?
After a few years I even stopped testing the water because as I learned what to do when. Ponding is a process, not a result. It should be enjoyable. Don't stress over it. Again, I found that with fish, plants, simple filtration and a large enough pump, nature took over and balanced my ponds. AND, I listened to Horton! He explained things simply enough for me to "get it" and didn't pontificate on the nature of algae or water chemistry that was beyond my intellect or interest.
Most people on this forum are very honest. They will tell you what they actually know and what they don't, but all ponds are different and you have to figure out yours. Just don't go dumping alot of things in the pond at once. You'll never figure it out!

Before folks start getting excited about whether you are adding "CHEMICALS" that will kill/destroy all life in your pond check what is being recommended and the dose. Stump remover is nothing more than potassium nitrate. It has NO phosphorous in it. The levels that are being discussed will create a temporary concentration of nitrate of less than approximately 5 ppm when you spread it around in your pond. The chelated iron levels resulting from the doses discussed will be less than approximately 0.1 ppm. The nitrate/potassium dose is less than the same you'd get if you fed a medium load of fish in your pond at the 2% by weight feeding regimen recommend in many aquaculture practices. This would be much more than you usually feed them, would result in a high load of organic matter being put into your pond along with all the phosphorous that is also present in almost any fish food I have been able to find. So by adding the "killer chemical stump remover" you are also avoiding the dependency (temperature and otherwise) for you biofilter to convert ammonia nitrogen to nitrite and finally to nitrate. I have done this with my pond for over a decade with no observable effects on my fish. And yes I have four large koi (one is 10 years old and about 24" long and the another is about 26" - 6 years old and the youngster is 12" at one year, the fourth one is only about 20" long and about 7 years old) plus assorted goldfish/comets. Maybe there is an organic form for nitrate, potassium, and iron out there but I have not been able to locate it...at least one that DOESN'T contain phosphorous, assorted unknown bacteria, viruses, high levels of organics which would very definitely impact on my pond and my fish. Adding this stuff should only be done if you feel your are having a problem with your plants such as water hyacinths. It is not a panacea for plants that are infected or diseased nor would I recommend this be done each and every week on a rigid schedule. Yes, it is possible to overdose but I'm assuming that most folks are reasonably careful before adding anything to their pond....fish, plants, food, salt, sodium bicarbonate, etc. Look at your plants and your pond. Do they look as if they need a bit of a boost? Okay, how are you going to do that WITHOUT upsetting everything else in the pond?

I personally have measured nitrate and iron levels in my pond every 15 minutes after adding a dose as mentioned above to observe what effect if any I would see. Essentially all of the nitrate and the iron were GONE (taken up by the plants) within 2-3 hours. I've been reasonably happy with the results: at the moment I have a couple of water hyacinths blooming; I'm in zone 4 and we'll probably have a hard frost tonight so this will be the end of almost all of the surface and garden plants.
---David

Ah Pat you are an exponent of the "KISS" factor. LOL
I treat my pond the same way as you. It becomes a second sense after a time, as you pointed out,in what you do or don't do. Sure mistakes were/are made and lessons were/are eventually learned.
Thank you for the kind compliment you paid me, but I detect you were already paying attention to what was going on in your pond and learned what works and what did not for it to be the success story that it is.

As to adding chelated iron in a liquid or powdered form, I see nothing wrong with that, if there is a requirement for it.
As long as people do not go hog mad, thinking that,as David said, "more is better" and stick to using chelated iron [or a handful of Muriate of Potash, once a month [or less], to boost the pond plants uptake of nutrients]I don't believe that anyone's pond is going to turn into a toxic chemical swamp with dead fish floating everywhere on the surface.

I have used a tablespoonful of chelated iron and Muriate of Potash, from time to time and seen a marked difference in the colour and quality of the plants. They have gone from poor looking pale green plants to dark green healthy plants in a few days.
I have koi and goldfish that are well over ten years old and are doing great. People who visit my pond remark on how healthy the fish and pond look.

Hawkeyefriend mentioned discolouration of the pond water.
Particulates in the water which can give it a brown tea like colour, I have found, can be reduced or eliminated completely by using quilt batting added to the filter.
Activated charcoal removes tannins caused by decomposing leaves from the pond water.
I noticed that in another thread the poster is looking for information about Protein skimmers/Foam fractionators in regards to removing particulates from the pond water.

To my way of thinking that approach is a total overkill for a backyard water garden, murky water problem, but if that is what the member thinks will do the trick then so be it.
Protein skimmers/Foam fractionators are expensive items to purchase and are normally used by some koi breeders who have a hefty investment in their pond stock and want pristine water conditions for the fish to swim in.
I have never seen the need for one in a garden pond.

The majority of folks we have on this forum want a neat little garden pond, with plants, fish and a few visiting frogs. Keeping it simple is their goal.

Back to the KISS approach!
"Horton"