Cindy is correct with her post.

Thanks Cindy for posting this so people know the difference.

I know that many indivuals will disagree with you, but Cindy and I HAVE BEEN THERE DONE THAT! And would rather not go back!

Bill

I dont post here much due to lack of time to be on several Boards.

What Cindy posted is very true. If you drain your pond to clean it after a few months, pick up a rock and inhale deeply. YouÂll be sick to your stomach from the smell. The accumulation of waste under those rocks will take hours to shovel out of the pond. Your fish, your pets that you are responsible for are living and breathing that disgusting, decaying matter 24/7. ItÂs no different than a toilet for them.

Your fish may be healthy and everything goes well for the first year but as your fish grow, so does their waste and the accumulation under the rocks. The work becomes more intensive and finally your fish, your pets, become sick and start to die.

Once a pond matures, the sides and bottom are covered with healthy algae so you really canÂt see the rocks. If you have rocks on the bottom, algae canÂt grow there. The only organisims that can grow under those rocks are anaerobic bacteria because they canÂt live where there is oxygen. There is little/no oxygen there. Healthy, aerobic bacteria cannot grow there. Take the rocks out. The pond will take less work to keep up and your fish will be much healthier.

So true Kntry. I had a short run of creek connecting two ponds and it has rocks in the bottom. Even that short creek got so filthy in a short period of time. So I put some hidden clean-out drains under the creek bed. Now I can open the drains and hose out the creek every couple of weeks to keep gunk from accumilating. I know how unhealthy rotting organics can be to fish and I don't want any area of my pond to become a septic tank.

Hi Cindy, I have read your post on here may times and only wish I had your knowledge of all types of ponds fish ect. I have seen some ponders fill the voids between the rocks which makes the waste much easier to remove and seem to be sucessfull. To me it does not seem worth the trouble but some just love the look of rocks. What opinion do you have on this option. Also does stacking rocks along the vertical sides cause problems you discribed?

I have seen many farm ponds that do not have any incoming water except for rain and do very well,of course if the are not deep enough they are susceptible to fish kills in the heat of the summer. Keep up the good advise.

Tom

Thanks Tom. I have seen flagstones mortared into the bottom of a pond and it looks pretty good. I think someone even installed a bottom drain. As long as the liner is well sealed to the bottom of the rocks with mortar, then it should not be a problem. Personally I don't care for that look much, because as soon as the rock is covered in algae, you won't see it anyway. I love seeing my koi with the black liner as their background.

Stacked stone along the side walls are still capable of trapping gunk...mostly floating fish food, but are not nearly as bad as rocks in the bottom. My biggest concern though with rocks on the walls is the fish can get cut up pretty bad on them, leaving an opening for infection. I have rocks stacked around the top edge of my big pond. they are submerged only about 6", but my fish have cut themselves on those rocks before. When I build my new pond and have a place to put my fish for a month or so, I plan to rework the top edge and will replace those sharp rocks with something smoother, like tumbled cobblestones. I'll mortar them all in so that no floating debris can get trapped behind them.

I also have seen farm ponds with no water flow in them, but those ponds are stocked even lighter than the numbers mentioned above. And like you said...those ponds are very prone to massive fish kills in the summer.

Great Post Cindy!

I have no rocks on the bottom but do have large smooth tumbled rocks on the vertical sides.
Every few weeks or so, I take my vacuum nozzle and get into all the crevices. You would not believe how much gunk collects there.

The liner is covered with a healthy coating of algae so it blends in nicely. You have to look hard to see it is lined.

I could not imagine the upkeep if I had rocks in the bottom.

Thanks. I can't imagine the upkeep either! As it is, my 9000 gallon pond takes me only a few minutes a week to keep it spotless. I never vacuum, and only have to deal with leaves in the fall (I net out what the skimmer does not catch). I cannot imagine how much trouble it would be to keep a pond clean if I had rocks! Many installers like to put rocks in the bottom because a huge part of their business is coming back year after year and cleaning the pond out. My pond with it's two bottom drains is self-cleaning. I only need to clean the filters, and that is a very easy job too.

I used to be an advocate of rock bottomed ponds. I, myself, had small river rocks/pebbles on the bottom of my pond until I did a rebuild this year to enlarge it for my growing number of koi. Suffice to say that the smell and the muck was enough to convince me that it was a grave mistake to have them there in the first place -- and I'm perfectly happy to admit it. I simply could not get the rocks clean enough to put back in, so I elected not to. I loved the looks of the rocks, but I really didn't want my fish living in that. I now have a bare liner on the bottom, but now that it has a nice covering of algae, it has a very natural look to it, and the folds in the liner that could not be ironed out make it look almost look like large flat rocks. The fish seem much healthier and happier and are much, much more active than they were last year.

I had to learn the hard way, like many of us do, but I'm pleased with the ease in maintenance now, even without a bottom drain. I use my pondovac 3 now and then and the filters pick up the rest. Removing the rocks was the best thing I have done for my pond and for my fish -- and for my back!

Good for you Nancy! I am sure your fish are much happier. You made the right decision!!

Cindy

Very informative post, excellent!
For the record I don't have rocks on my pond bottoms, but I do have them in a stream/falls connecting two ponds. The water has a good stread flow to it, and the stream portion is heavily planted. Do you think there would be the possibility of this becoming a problem? I don't have koi, but goldies. My upper pond is only about 150 gallons, heavily planted and had 2 4 inch common goldfish. Then there is about 4 feet of falls/stream, then my main pond of about 850/900 gallons. Again, lots of plants, bare bottom, and has 1 common goldfish (5 inches), 3 shubokens (4 inches), 2 sarassa (3 inches) and one comet (2 inches).

Thanks again for the great information. Can't see why anyone would get mad over the post, better to have the knowledge than not have it!!

Derrick

Rocks and pebbles in the stream bed is different than rocks on the bottom of a pond because there is a continuous flow of water. This creates an excellent bed for the beneficial aerobic bacteria. I have river rocks and pebbles in my stream also, and I think most people do as well.

I'm clipping your excellent post for future reference, Cindy! :)

Brenda

Well, going on eleven years with my rock bottom and still waiting for the dreaded problems to happen. DIY filter, no bottom drain and NO annual clean out. No annual algae bloom either.

Until a kingfisher got most of them this past winter I had my original goldfish from 1997 still fine and dandy.

Have only had about six deaths over the years that weren't predator related. Was not buying new fish every year.

I will never be convinced that rock bottomed watergardens are evil.

Would I put rocks in a huge show koi pond? No, I would not, you can't see the bottom in big ponds like that but in my 900 gallon goldfish pond, or in anything smaller, I don't want to see the liner or any pots.

People shouldn't keep koi in many of the ponds they do keep koi in and improper filtration and waster depth and quality is likely a huge part of the problem often attributed to rocks.

I love that there are other people that get it! I do construction and maintenance and I would not be over estimating that 60 - 70% of the 'bad' maintenance is from overstocking and over feeding koi. Now I love koi, but if you want a low maintenance pond that you can enjoy you've got to plan ahead. 1000 gallon per medium to large koi (appx 2') is very correct with standard filtration. (side note those 6 inch koi will grow to 2-3 foot is fed well) Can you do more, yes, but the ones you see on display or on tv have more extensive filtration than 90% of the people on this forum or that aren't 'professionals'. Thats not insulting to the post/viewers, its just the truth.
Also, I could easily throughly clean 4 liner bottom ponds before I could get through one rock bottom. Now I will state that there are some professionals that will strongly argue the rock bottom facts...but they are professionals that install 5 to 10 times the filtration that a DIYer or most 'pros' would do. I went to a pond-build in St. Louis and we covered a medium sized water garden with rock. But we also had well over 10,000 gph on the pumps with bottom drains and multiple skimmers. Can a rock bottom pond emulate a natural pond . . . yeah, but you have to have some massive hardware and lots of work to pull it off.
Thanks for starting a string that is really worth everybody reading. If we could put stars and 'must reads' by strings this would be one of the top ones. Great!

The place I buy my pond supplies has several gorgeous rock bottom ponds, and they've been there for years. They are overstocked with huge, beautiful koi that I would give my eye-teeth for. I'm sure they're probably cleaning it somehow after hours, but it looks very natural, and I love to go there just to look at the ponds. ;-)

The rock bottom didn't work for me, but I do know others who love theirs. If you're ever in the Tulsa/Bixby area, stop by Hardscape Materials on South Memorial. I'm not promoting the business, but it's worth the trip just to see the ponds and the koi.

I can totally agree with the rock-bottom pond accusations only for those people who are not responsible with their rock-bottom pond. Yes, a rock bottom pond IS more work, but you have to give and take if you want a "natural" look. I do not mind the monthly vacuuming. I could never imagine my pond w/o rocks on the bottom because it looks so much better than an unnatural looking, plain black plastic liner. Some people are ok with this look; I'm not.

The accusation about "gas bubbles" surfacing - I've NEVER had this happen, and I'm assuming this is a result of someone not maintaining/cleaning their pond and letting debris mound and settle for long periods.

What bothers me is that many on this site say rock bottoms are sooo bad, kill your fish, etc. but you can't say that about all of them if the ponds have RESPONSIBLE owners such as myself. I would never let my pond build up with debris. I care about my fish and want them to be healthy. There is more maintenance to rock bottoms, but I deal with it and do it responsibly.

Always_outside, the reason you haven't had any problems is because YOU do monthly maintenance and keep the rocks clean. The vast majority of rock bottom pond owners do not have time or the desire to do all that work, so they just don't bother. Sometimes they hire professionals once a year for cleaning, sometimes they don't. They just let it build and build and build, and one day they begin to have problems. For many people, the plants are the priority and the fish are secondary, and it's easy just to buy new ones when they die. That attitude makes me sad. I have talked to people who had sick fish. The fish were sick enough that they needed the pond to be salted to help save their lives. The pond owner was too worried about the plants to risk salting the pond, preferring to just buy new fish instead.

So yeah....rocks can be done, if the pond owner is responsible enough to keep the pond clean with frequent vacuuming and possibly a yearly total clean-out.

Watershaper, sound like you understand how to do it the right way. Most small "aquascape style" ponds are not done the right way. They are heavily rocked, under filtered and overstocked. But it does sound like you are doing a good job building them.

I have a water garden pond similar in age and size to the one described by buyorsell888. I have a clean bottom, but I do have medium size river rocks on my plant shelves. I too have very clean water and have lost very few fish over the years. All my fish deaths happened during mating. I lost 1 fish from stress and 2 jumped out of the pond.

I have goldfish and would never consider adding koi to my 1,000 gallon pond. A single adult koi would probably equal the waste load of all the fish I currently own. My pond was built for sight and sound. It happens to accommodate the needs of a small amount of goldfish. A koi pond is designed for the needs of the fish.

I'm sure a pond with a stone or gravel bottom is going to have major problems if it contains koi. The amount of waste the fish produce is the determining factor.

Some people have water gardens that contain many plants and a small amount of goldfish. Others have koi ponds that are designed to accommodate the needs of a larger fish load. These two types of ponds are completely different environments. Something that works fine in a water garden may cause major problems in a koi pond. Many koi pond solutions are not relevant to water gardens and many water garden solutions may not work in koi ponds.

I don't vacumn more than once or twice a year and I have never drained the pond to do a complete clean out. I do have a lot of plants growing right in the rocks including anacharis on the bottom and always have clear water. My fish don't have ulcers or fin rots.

My pond is NOT a koi pond, it is much too small at 8'(from waterfall to front) x 13 (side to side) x 2-1 (depth) and approx 900 gallons for koi.

Many keep koi in ponds too small and too shallow. I won't.

{{gwi:206682}}

Slightly OT, I was visiting a friend the other day and she mentioned she had a neighbor that had great landscaping and a pond so I peeked over the fence.
What I saw really bothered me. The pond was about 3-4 feet wide and maybe 6 feet long with a small waterfall. The pond was rocked lined and only about 18 inches deep. It was covered in water hyacinth.
All of the sudden 5 12-15 inch koi flopped over each other to get to the edge thinking I was going to feed them. They were so cramped they could not move without having to slide over each other.

1sst,
That is very sad. I hate it when people get pets (whether dogs, cats, birds, reptiles, fish) and let them live in filth or just ignore them altogether. It is really cruel. They have beating hearts, emotions, personalities and needs. You may want to consider calling animal control to help find homes for those poor koi that are cramped in an environment they shouldn't be in.

Ccoombs1, I appreciate your advice. Don't get me wrong, I believe in everything you stated on this post and others. I do regard you as one of the experts on this site. I really do look up to you and others on this site for information and guidance. I guess it just makes me feel bad hearing that my rock bottom is bad for my fish when I take all steps (above and beyond) to keep my fish happy and healthy. I am definitely not lazy when it comes to my pond. My husband knows that I'm out there several times daily checking on them, testing the water, feeding or cleaning. My pond is probably cleaner than my house! LOL! I can see how people who DON'T vacuum/clean out their ponds regularly can have an enormous problem with debris, filth, and gases that you speak of. It's only natural for that to occur when the debris has no where else to go and becomes trapped under the rocks. I just can't imagine anyone letting it get that bad! Where is the pride? The love for the fish?

Many of you referred to vacuuming your ponds. I have a 2000 gallon pond with no filtration, no skimmers but would like to be to vacuum the plant shelves on occasion. No rock except 2 small rock walls containing gravel beds for marginals. No koi but a 7 goldfish. Pond is fairly well stocked with Japanese iris, lilies and other pond plants.

Would like your recommendations for pond vacuum cleaners. I would think wet/dry shop vacs would be unsuitable because of their limited capacity but may be wrong.

Dale

Buyorsell888, I think some posters are giving advice based on koi ponds and water gardens are not the same thing. My pond is similar to yours as you can see below. The photo is 5 years old.

My dog is out in the yard quit a bit during the summer. She does leave some piles that I clean up with a scooper. If I had a cow, I'd be picking up manure piles with a shovel and filling barrels. Koi vs. goldfish is a similar situation.

Lsst, I also see small ponds loaded with koi all the time. I don't know what the fascination is with koi. I enjoy fantails myself.

Turkeyguy, I drain my pond down past the plant shelves and clean them with a shop vac. It works great. I also have a pond vacuum that runs of the water pressure of a garden hose. I have strong pumps to support my falls and most of the fish waste and sediments are sucked into my filtration system. I would look at mechanical filtration. Also, do you have a bio filter?

{{gwi:206683}}

I have an Oase Pondovac 3, which is pricey but can sometimes be found at a reasonable price on eBay. That's where I bought mine.

Or for the DIY'ers.................This has been the standard for years.....................

Thanks for the responses. Floyd's pond vacuum looks interesting and will be considered. I don't have mechanical filtration as no electricity to the site (use extension cords for sump pumps). I am trying to keep the pond well planted with minimal fish load to achieve a natural balance as possible. I do plan partial water replacement periodically and to vacuum debris off the 2 shelf levels.

Dale

Dale, filters don't use electricity. They rely on a pump.
I have a pressurized filter that uses a standard pond pump to force pond water through various filters before returning it to the pond.

I don't like extension cords on the ground, but as long as your using them you can do the same for a pond pump and filter.

Some of what Cindy posted is true except for this section
Water changes:
Natural ponds are normally spring fed or creek fed. Most have a large spillway somewhere, and if you measured the flow you would see that thousands of gallons of water per hour is flowing out....and new water is flowing in at the same rate.

Most people have no idea what a natural pond is. The things that are stream fed or creek fed usually aren't ponds. They are pools and are usually formed because water has etched away the limestone and created nice partially calm reservoirs for water. In Spanish they are called Cenotes and they are not anything like a pond.

Most natural ponds are really retention ponds that have nice thick clay bottoms and get their water from run-off from the surrounding higher land or rainfall and they might have some rocks but they are usually covered up by sediment.

Other natural ponds form in low spots where the ground water is close to the surface and when the level of the ground water goes down the pond loses water because the bottom is very porous.

Natural pond aren't surrounded by rocks because they occur in pastures so they are surrounded by grass and water plants.

Interesting thread. I'm a marine aquarist who had a maintenance business for reef tanks. I wonder if the problem is indeed lack of maintenance on the rock-bottomed pond. With proper periodic cleaning, it would seem to me that the aerobic bacteria would still thrive, and the small amount of anaerobic bacteria would reduce the nitrate levels, as they do in a reef tank with a live sand bottom and live rock. Or are the ponds and aquaria not comparable in this regard?

Great reading thanks to all. My husband and I hand dug our pond last April and we stocked it six weeks later. It is 11'x 8' and has a slanted bottom and is 29" at the lowest end. (no bottom drain)I had three koi 12" 10" 5" and eight goldfish 6"-7" long. Last fall the goldies spawned and now I have about 15-3" babies total of 26. The pond was rocked with smooth rocks (med sized) and large 2"-3" pebbles. I removed my rocks and pebbles and now I covered the edge of the liner with flagstone. The sides are stanted and 10" deep to the first shelf so the rocks are pretty stable. Looks like I will be cementing the rocks. Do I need to drain the water down to the first shelf before I cement or empty the pond?
I think I should maybe get rid of the koi and only keep a few goldies so I can have a healthy pond.

Its amazing the variety of responses when we get into threads like this one. Always outside makes a very good point that if you are willing and have the time, the appearance of a rock bottom pond is second to none. My suggestion to people considering a pond would be to realize that to keep a rock bottom pond clean it will take much more maintenance, whether hours or dollars, or much more filtration and hardware.
We all make suggestions based upon our own experiences. Myself . . . I am yet to see a rock bottom pond that isn't in dire need of a clean out or stressing the fish (especially overstocked koi). Everything is algaed over so why did you pay for that pretty rock that is just green like the liner? I see why the 'big box' companies do it, you sell more rock, but those companies are just in it to make money, not to make an enjoyable, low maintenance pond.

Here's the deal plain and simple, does this mean that you can't enjoy a rock water garden, of course you can. Just realize that the only post I noticed defending rock water gardens was someone who mentioned that they get in the pond and do maintenance every month! Now thats my job and I strangely enough enjoy doing that also. The question is would you???

I do not get in the pond monthly to do maintenance and I have rocks on the bottom and it is a healthy pond. We have had ponds for over 20 years and have had no problems. Of course, we are not overstocked on fish, nor do we overfeed them. In addition, we use no chemicals. Yes, there is algae, but not too much. **Saltydad said, "With proper periodic cleaning, it would seem to me that the aerobic bacteria would still thrive, and the small amount of anaerobic bacteria would reduce the nitrate levels, as they do in a reef tank with a live sand bottom and live rock." It has been my experience that this is similar. My spouse owned a aquaria store for many years and that scenerio worked perfectly for us.

I am rebuilding our pond right now. It had a 120 gallon preformed pond for the bottom pool, but I dug it out and am replacing it with about a 1,600 gallon hand-dug pond with an EPDM liner. I can't afford all the hardware right now for a bottom drain, but I think I would like to have one. I thought that I could go ahead and plumb for one right now, putting the bottom drain in and then running the plumbing a few feet out from the pond -- then just stub it up and cap it for now until I can get the rest of the equipment I need. Does that sound like it would work? I'm not quite sure how bottom drains work, or what is needed. I need to research it more.

dang it....I had a really well though out response all done, and my internet explorer crashed. So I'll try again...lol!!

First...a few comments regarding how koi ponds compare to aquariums. Normally, aquariums are lightly stocked with small fish. It's really easy to keep the ammonia/nitrite/nitrate cycle operating perfectly in a correctly stocked environment. Same as a rock bottom pond...lightly stocked and properly maintanied it can work. In a pond's bio filter, ammonia is converted to nitrite and then to nitrate. Nitrate is most easily removed froma koi pond by way of regular water changes. Ever try to keep an aquarium with goldfish? Many goldie keepers I know keep no gravel in the tank at all, because of maintenance. That gravel gets really filthy very fast. I had a lovely goldie tank once....and gave it up. the maintenance was a nightmare! I'd rather deal with a huge koi pond any day of the week.

Some people are reporting sucess with rock bottom ponds and no maintenance. Again...it is directly related to stocking levels. I hope these ponds continue to perform well for years to come, but for the vast majority of people, they will not. Most watergardeners install their ponds (and rocks) and then run out and buy a bunch of adorable little 5" long koi. The koi grow.....fast. They produce mountains of fish waste, which all gets trapped in the rocks. But because the pond looks clean, the owner is lulled into a false sense of security and does not think that there is a thing wrong, until the fish start dying or the fins start rotting off. Then they do one of two thing....they learn where they went wrong and correct their mistakes, or they just buy new fish (which is unfortunatly what most people do).

Matt...you are on the right track with your new pond. You certainly can install your bottom drain now and add the rest of the system later. But instead of using a pipe cap, install a 4" ball valve on the end of the line. The water can't be permitted to sit stagnant in the unused drain line for too long or it will start developing the dreaded hydrogen sulphide gas. Opening that valve every couple of weeks and allowing the water to flow out for a couple of minutes will prevent the problems.

I am attaching a link to the Atlanta Koi Club's web site. They have an excellent pdf that explains a lot about how a koi pond works, water quality, stocking levels, how much biofiltration is needed and many other wonderful facts.

Cindy

Violet, are you talking about using cement on flagstone that is used around the edge of your pond? I don't thing you will have a problem with surface flagstone at the waters edge. As your pond edge is sloped, any sediments are going to sink to the plant shelves or bottom of the pond.

I never owned koi, but I would say a pond of your size might be too small. My pond is a little bigger and I would never stock it with koi. That's just my opinion.

Your goldfish seem rather large. I Stocked my pond with a few 3 inch gold fish a decade ago and they are still swimming in it Today, but the largest is probably less the 6 inches. My fantails are probably 4 inches with chubbier bodies.

My fish spawn every year, but I don't get many additional fish. I think most of the eggs and baby fish are eaten. I had four small fish last fall and gave them away. I never had a baby fantail, so the four I own must be the same sex or their babies are eaten. I try to keep the population stable at 12 fish.

I don't have rocks (except in my head if you listen to my wife!)LOL, but I do have a possibly dumb question.

When you are looking into the water, you know how most things look about the same depth, regardless of how deep they actually are, and how difficult it is to judge between something sitting an inch off the pond floor compared to four inches off? Why doesn't someone make a liner with a rock print on it? Literally something printed right on the liner in water proof and fish safe paint. That way there would be no worries of gases being captured under the rock, because there are actually no rocks there, but it would still give the look and appearance of having a rock bottom.....just a thought....LOL

derrickm,

A couple of years ago there was a liner that had a rock pattern printed on it. My local HD carried it. I have not seen it in a couple of years so I do not know if it is still being made or not.

How do I attach pictures of my pond in this forum?

Violet, check out the link below.

Brenda

Lots of excellent information, ccoombs1, and I agree. I would only wish to clarify--when you say "fish", you mean Koi, right? Koi are the big eaters and big waste producers.

A rock-bottomed water garden with a few mosquito fish or a rosy minnow and no Koi is probably good for years with little maintenance. The same pond with even just a couple of Koi in it would be a whole (unhealthy!) different thing.

(Of course, the same hypothetical water garden stocked somehow with tens of thousands of goldfish would be a problem as well).