Susan I think chemicals are bad for your pond and I have been ponding for many years. I don't know what Microbe Life or GreenClean contain so I am not sure if they are harmful. But the best way to keep a pond healthy and happy is to keep if free from debris that settles on the bottom, filter the water and make sure it has lots of oxygen. If you don't want to add filtration the concentrate on debris removal and water changes. There are so many ways to filter your pond. Many people vacuum the pond bottom, some use retro-fit bottom drains to keep the bottom clean and those who are newly installing a pond will include a bottom drain to their ponds. Filtering the pond is important to keep maintenance at a minimun. You need to remove as much debris as possible with a good filter and make sure you have biological filtration as well. For example I have two circuits of filtration. My skimmer has a 57 watt UV light and all the water that is drawn from the surface goes to a big DIY filter that uses foam, plants and Savio springflow to help with the mechanical filtation and the biofiltration. My bottom drain goes to a settling pond in which the debris settles to the another small pond and it is cleaned out a few times a year. Since your pond is concrete then a retro-fit bottom drain could help. But vacuuming would work as well. When I first started out ponding I would vacuum my pond with a pump that I held with a small rope. I used that and a net to get out debis. Very low tech but worked well. I would then add fresh water to replace what I had taken out. Years go by and I have experimented with underground filters, Bead filters and DIY filters. When I rebuilt the pond (a few times I admit) the bottom drain attached to a seperate pond made maintenance much easier. So you just need to find the type of filtration that suits your needs. At the very least keep the bottom clean and do some water changes during the season. This is a very simple way to keep your pond healthy. Also the catfish will not hurt your fish. When I had my catfish he co-exsisted very well with the Koi. RIP Wayne. Lisa

Hi Jenny, First, the more important questions: Nope, leaf peeper season hasn't started yet! That's usually the end of September - first week in October (for the Champlain Valley). Already many motels and Hotels are booked solid. Shoveling snow?? When one is retired it is irrelevant. You get up, you look out, you say "oh, it snowed last night; looks like 18". Isn't it pretty". You have another cup of tea/coffee; go back to bed or not. Wait until Spring to shovel out. Not-a-problem! Now to your questions: First let's deal with some heresy: a hole in your ice DOES NOT MATTER! Gasp! WHAT DID HE SAY??? Nope, it's all about providing a surface for gas exchange. IF... you're using a heater, a light bulb, stock tank heater, etc. then it IS about keeping a hole open since that is the only surface over which the gas exchange can take place. However, with an aerator the gas exchange surface is in the bubbles...NOT in the hole that may or may not be in the ice. All that air you pump in there has to go somewhere otherwise you'd have the equivalent of one of those air-hockey games only with an "ice puck" floating on an air cushion! But that doesn't happen...the air finds a way out - through a crack, through the edges, though a hole. So if it "domes over"...so what? The air is STILL finding a way out. And because you are pumping air in it is the aggregate surface area of all those bubbles that is providing the surface area for gas exchange...and it is HUGE! With a stocktank heater in our neighborhood with our winters you might get a few square feet for a hole although at -20F you might find it disappears! But the aeration approach continues to put out 10's of square feet of surface area every minute!!! As a result not only will you keep more than enough oxygen in there (not really that much of a problem given that the metabolisms for the fish are almost non-existent as well as the microbes involved in consuming organics - and oxygen - aren't doing too much...but still not exactly zero!) but you will be stripping out ammonia and carbon dioxide and other gases you wouldn't want trapped under the ice. This is the real benefit of the approach to using aeration. As to the plastic tent? Not sure it does too much although it does allow me to see the hole for an extra couple of months. But I've had it get ice inside, even an inch or so ABOVE the water level... but still not really relevant as long as the aerator/bubbler is doing it's thing. Note the ice auger in one picture...I went out to check one fine February day (think high of -10°F!). Couldn't really see a hole in the ice under the teepee. Drilled a hole and looked...yep, everything was working fine. But the ice melted out under the teepee more about a month before it melted out of the pond so there is some solar benefit. The real purpose of the floating thing is to hold the aerator above the bottom of the pond. As to adding a stock tank heater on the coldest days?? I wouldn't bother. If you lived in zone 6 or 7 you might have some impact on the temperature in or around the heater but in my zone (and I suspect yours) adding even a 2500 watt heater is akin to performing a particular bodily function into the wind! Yes, it probably will melt out a hole, but once the heater is down near the bottom of the pond with an outside temperature of say -15° or -25°F I suspect there will be no measurable impact on water temperature. Having a heater on hand, however, does provide a way to work on thawing out a line if it develops an ice plug. I don't own a heater since, as mentioned above, I use other approaches for that problem. Like I said.. it works for me and as posted in the URL above it works for other folks as well. The problem is to understand that you are not really trying to HEAT the water to some acceptable limit but rather maintain a surface area open for gas exchange. I like cheap. I like what works...and so far, over several years, it has worked for me. The biggest factor will be whether your pond depth and volume will provide the heat transfer necessary to keep a water layer below the ice, i.e., making sure the whole (no pun intended!) thing doesn't freeze up! ---David

Like many have mentioned, there are convincing arguments for both. Here are two sides to this that I copied from the old rec.pond discussion group back in 1999. As for me, I have no rocks in the bottom of my pond except for the ones my Koi knock out of the planting baskets. Rocks in the Pond Introduction Below are two statements for putting rocks in your pond. One statement is for rocks and one statement is against rocks. I have no opinion ;-) and will stay neutral on this subject as long as I am keeping the informal rec.ponds faqs. FOR ROCKS Subject: rock vs no rock From: "Glenn Rieker" There are two schools of thought in watergardening as we see it..............the old timers are set in their ways saying simple liner ponds are the way to go.........I think these are the same people who may still listen to 8 tracks.....:) I can't tell you how many people come into our garden centre and tell us they have read this book or that magazine and they installed their ponds like that and they constantly have challenges...as I have told them most of these authors are just that, great writers, unfortunately as a group they have probably installed less than 10 ponds, we do this on a daily basis and must answer to our demanding clients......one school of thought is you need to "filter" your water.....like a sewage plant.....the other school of thought we prefer is to create an "ecosystem" Most of the "filters" out there are based on sewage treatment plant design and/or chlorinated pool systems which are sterile.........The email I had an opportunity to review mentioned the appearance of the bottom of a watergarden is a judgement call .....Hmmmmmmmmmm.....let's see........when I was out west in Yosemite and the Tetons I can't tell you how much I longed to see a clean black liner on the bottom of those rushing crystal clear rock bottom streams in the park :) Rock bottom streams and watergardens win the aesthetic award hands down. But Glenn..........what about maintenance?????????? Well, we drain the pond down in the spring and wash the stones down and the pads in the skimmer and falls and fill the pond back up with water, salt and bacteria....during the season we have an automatic fill valve in the skimmer to top off the pond while we are casually resting on the back deck instead of pulling hoses around......in the fall we set up our fall netting protection because even skimmers can only handle so many leaves and then take it down in late fall. In the meantime we have enjoyed the crystal clear water, healthy fish and lily blooms galore from the plants planted directly in the bottom of the watergarden.......not one time did I have to trapse into the watergarden to clean a pump intake.....or have cloudy water....... Can you have crystal clear water in a simple liner pond.........yes, we did it for seven years until we saw "the light".........now my life is simple, create watergardens with considerable less calculations, crystal clear water, happy clients across teh country and no more headaches!!!! Our business model is based on focusing on success, not failures......I have not had the opportunity to visit this site due to this being obviously our busy season....but when I looked today the questions and answers are still the same...........Unfortunately Doctors are the same as this newsgroup...........they treat sickness.....they are not taught to promote health......ever have a 300 lb. smoking doctor tell you your blood pressure is high???? I am sure this commentary will raise the ire of the usual people in this newsgroup, however, I feel I need to tell you how "I" see watergarden development changing on a daily basis..........don't get me started on the Koi Gods and how you have to have a $20,000 filter system that takes up half of your basement and bottom drain to keep their championship fish. We have happy, healthy fish worth thousands in our ponds and they love the rock bottom..... -- Glenn Rieker BS Landscape Architecture Remember.....Life is a game don't live it on the bench! http://www.gardenhaus.com AGAINST ROCKS IN THE POND The Case for Smooth Bottom Pond Design: Todo --- North Florida Koi Club, Past President & News Letter Editor todo@cybermax.net Recently there has been an ongoing debate on the news group rec.ponds discussing several ponders preference for ponds with a layer of gravel across their pond's bottoms. Among their reasons for this are 1) The light bottom makes the fish easier to see, 2) the gravel is more attractive than a smooth black liner, 3) what possible difficulties that may occur due to trapped organic matter can be solved by biological and/or chemical means. There are however, real reasons to reconsider the decision to place gravel in a pond. The bottom may be lighter in color, but often times this light rock gets covered with dark green algae, which defeats the intention. The gravel can get covered with mulm, the dark organic material that is a byproduct of the natural biological functions of a pond. The mulm can totally or partially obscure the bottom. Hence, it is an open question how long the bottom will stay pristine. As for the aesthetics of the gravel. There is not discussion on taste so this becomes no real argument for or against this question. The third point is then the most critical and most contentious. With a gravel bottom the mulm, fish waste and decaying plant matter from the pond does not flow quickly to the drain or sump, where it can be removed from the pond. The gunk gets trapped in the spaces between the stones and there it sits. In a properly designed pond the solids produced in it are carried by the flow of the water down to where the pump can suck the material out and send it to the filter system where it belongs. (Please note that I do not imply that a pond with gravel is by definition poorly designed, for there are many smooth bottom ponds whose specifications do not add to its efficiency. However, I do say that no matter what the design, gravel degrades the efficiency of a pond). What then, is the detrimental effect of having gravel. The first thing to remember is that a pond is not an aquarium outside. Gravel, used in an aquarium has a purpose, it acts as part of the filter system. Water is drawn through the gravel, mechanically removing debris and providing a surface for aerobic bacteria which neutralize ammonia and other byproducts of the aquarium system. The water is then pumped back into the tank. In a pond there is not under-gravel filter. Water is not drawn through the stones, it passes over the top and the mulm that accumulates under and between the pebbles builds up in an oxygen deficient environment. As a rule, aerobic bacteria are beneficial and anaerobic bacteria are not. Anaerobic bacteria survive without oxygen and their byproducts are often harmful, such as sulfur dioxide, the chemical that give a rotten egg smell. In addition to these bacteria, other harmful organisms fester in the goo at the bottom of gravel ponds. To counter the foulness of the gravel bottom, practitioners say that chemicals can be used to reduce the mulm to an inert material. There are other products, such as PondZime which reduces the mulm with enzymes. The efficiency of these remedies is questionable, not to mention that even if the crud is neutralized it still continues to accumulate. Hence, more chemicals must be used to deal with the problem. It seems that a much better, less costly, and far preferable solution is to have the pump remove the gunk. Here, a counter argument says that the mulm is only deposited in the filter and so it doesn't matter where it sits, in the filter or on the bottom, it is still in the pond system. This argument fails when the mechanisms of filtration are known. For in a filter system, water is passed though the filter, supporting aerobic bacteria just as it is in the under-gravel filter in an aquarium. So the issue comes full circle just as water is pumped from a pond, just to be filtered and returned. The idea of having gravel comes from aquariums, but as ponds are different than aquariums the function of the gravel is shifted to the filter system in ponds. Ironically and in opposition to the logic of some ponders, the gravel becomes detrimental to the pond.

Consider doing some serious research. Asking people for opinions only gets you opinions which are almost 100% passed back and forth so many times people actually start to think they're facts. You're doing pretty good. You already understand no nitrite means no bacteria. You used the term "total ammonia" too which is good. You're already smarter than the average bear. Let's bump it up one more notch. Lets start with the easy stuff. You don't mention the temperature of the water but I have to assume it's pretty cold. Nitrifying bacteria slow down as the temp drops. At 39F they stop. At 46-50F they only work at 25%. So trying to get a bio filter going is a bit silly in most climates in winter. Moving the fish back to the pond has the same issue, no working bio filter. Moving them back to the pond must work cause that must be a safe place cause millions of ponds overwinter fish without loss. Must because of bio filter...right? Nope. A little harder now is the term "ammonia". When pond people talk about ammonia they almost always think of it a chemical. That's a problem. Ammonia in the pond is 2 chemicals, NH3 and NH4+. They're kind of the same, the difference is just ions. But ions are the thing doing the harm to fish so kind of important to us. What's an ion? Forget about it...not important to us. We only care about how to keep fish safe. There are lots of terms for NH3 such as "free ammonia", "Ammonium hydroxide" and probably what most people just call "ammonia". Let's make it simple and call it "deadly ammonia". This is really what scares us. Lots of terms for NH4+ too "ionized ammonia", "ammonium". Lets call this "safer ammonia" because for fish that's what it is, safe. Most tests are for "Total Ammonia" which of course is the total amount of deadly and safer ammonia. So a total ammonia test by themselves tells you almost nothing when ammonia is detected. There are test kits for telling the difference between deadly and safer ammonia but most people use total ammonia tests. This causes lots of fish deaths as people do all kinds of crazy stuff to lower ammonia...which may have been safe to begin with about now fish are stressed by the "fixes". The weird thing is deadly and safer ammonia go together. You always have both. And they change from one to the other in the blink of the eye as temperature and pH changes. As temp drops "deadly ammonia" converts to "safer ammonia". As pH drops same thing "deadly ammonia" converts to "safer ammonia". As temp and pH go up safer turns into deadly. You've been raising pH, or trying to keep it up, and have been cheered into doing so, to get a bio filter going which probably can't start due to low temps. Keeping the pH up is also busy converting safer ammonia to deadly ammonia. For example there will be about 90 times less deadly ammonia when pH is lower from 8.5 to 6.5 at 68F. By letting water temp fall and letting pH go down the fish can be safe even when total ammonia tests are crazy high. My suggestion is to find a ammonia - ammonium chart on the web you like and use that along with your pH test and water temp to determine first if you have a problem. It's likely you don't have a problem...but are doing things that could cause problems. If you have a problem then water change is the best option imo. Adding an ammonia binder means test results will be meaningless and you'll be flying blind. If needed water changes are often you could consider a 24/7 drip water change. Even with treated city water these can work. I also suggest letting water temp fall to around 40F. Converts most deadly ammonia into safer ammonia and almost stops Aeromonas bacteria from growing. I would not let water stay below say 37-39F for days. Lots of people with froze over ponds think the water temp is near 32F but that's another myth. Fish under ice in a backyard pond are likely enjoying a 39F temp. With an above ground tank the water temp can drop below 39F, even below 32F so you have to keep the temp up a little. Low temp also lowers fish metabolism which reduces ammonia production. Natural selection kind of worked this all out for us...as long as we don't "fix" it. I suggest letting pH fall to wherever it wants to be. You could force pH lower if you really wanted to, knew what you were doing, AND actually had a deadly ammonia issue AND water changes were a problem for some reason. Be really careful of people saying pH should be this or that range. They almost never know what they're talking about and are just repeating what they heard from other repeaters. In reality it's almost impossible for normal water sources to have deadly pH levels. Trying to push pH into some made up range with little understanding is more dangerous. Some other small points...size of the tank doesn't really matter. Sure, bigger the tank the slower ammonia becomes of problem...but it's likely to still be a problem. All the rules of thumb on ratio of water to number/size of fish is a bit silly. Just made up number out of thin air. Fish are kept safe with testing and understanding. Most city water now days don't use chlorine but instead uses chloramine. They sound the same so most people think they're the same and give the same advice they did 20 years ago for chlorine. Chloramine is made by adding ammonia. When we add chemicals to remove "chlorine" that ammonia is released which is why those pond products add an ammonia binder. And why total ammonia tests become useless even with temp & pH charts. Adding binders means you have no idea what's going on ammonia wise in the water unless you have specific tests for the binder.