Lessons Learned After 6 Months
Of Running The Test Pond

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Test pond is a must!
When I built my test pond, it was primarily a learning experience for working with concrete & block, but it showed me so much about other factors which are very important to enjoying your pond. Like is it in a convenient location? Will I go visit it once a day, where it is? Will there be very many leaves in the pond? Does the water trickle noise annoy me at night? Etc. So before building your pond, I'd strongly suggest setting up a quick & cheap pond and running it in your location for 6 months to a year. Home Depot has cheap performed pond liners that you can setup in no time, you can also get stock tanks from horse supply stores. Give it a try and see before you do the heavy construction.

Drylok Sucks !!
Cinder blocks, concrete, mortar mix, it all leaks like a sponge. I used drylok to seal the pond and it was great for about 6 months then started to leak slowly. I emptied the pond and found that the walls of the pond were sealed great, but the bottom had numerous spots where the drylok had released from the concrete. I followed the instructions exactly when applying it, and for a while wasn't sure what went wrong. I repaired it with more drylok, then other places on the bottom started releasing. Very strange that the walls were perfectly sound, not a single release. Then I chatted with some of the local koi club members and turns out they had very similar problems. Drylok is great for holding moisture in, but if moisture comes from the back side, it will get the drylok to release and there goes the leak. Makes sense - the walls were above ground, but the bottom was in contact with the dirt, when it would rain the moisture would soak upwards from the bottom and cause the problems.

What to do? The guys suggested Pond Armor to do the repairs, it is basically expensive epoxy that has a color additive. Its really really expensive, and for a large pond it would be beyond what I could afford. I thought about polyester resin, but unless you use the type with wax in it, the surface won't fully cure and it will secrete toxic chemicals into the water. For a big pond, others have suggested Thoroseal, its a regular masonry product that is a waterproofer for concrete and block. Its pretty cheap, available at masonry supply stores, and is easy to apply.

For my little block pond, I had some sailboat type epoxy and just cleaned the surface well with a wire brush and putty knife, then painted epoxy on the surface. Didn't use any type of cloth, just apply epoxy direct to the pond with a brush. Works great, sealed up the problems with the drylock. If I run into any future issues, will just dry it out, sand down, and apply more epoxy. Thats how I repair boats....

Algae Bloom & UV Sterilizer
I read somewhere that you don't need a UV sterilizer if you have a good rock filter, and you keep enough plants in the pond. Something about the nutrient balance prevents the algae. Well, after a couple of seasons of running my pond and learning more about it, a pond can balance itself out so the algae on the walls will eat all the nitrate and prevent the pea green soup, but it is much simpler to just hookup a UV sterilizer on it's own pump and clear it out. So I bought a UV sterilizer off ebay for about $70, and it cleared the water up by the next morning, and has stayed clear ever since. Cleared up a little too quickly, I had a common israeli carp in there at the time and it jumped out the next day and dried out / died. They are skiddish, and will jump when ever their water changes too drastically, so I should have put a net over it.

String Algae
My wife bought a lilly pad kit at the pet store, it was basically a dry ball of weeds inside a net bag. We put it in the bottom and it quickly sprouted some stems with lilly pads on them. Pretty cool, but then a new algae started covering the walls, I think it came with the lilly pads. Now I have a velore / velvet looking coating to everything on the inside of the pond. The fish often bite off chucks of it and eat it, and anything that breaks free goes thru the UV sterilizer and is killed, so the water is still clear.



Water Temperatures
Above ground ponds have a common problem, their temperatures go up and down rather drastically since the water isn't insulated with the dirt all around it. I knew this when building this pond, but didn't want to take the time to dig a hole, plus this is only a temporary pond to learn from. In the winter, the water temp of my pond was down around 44 degreed, and in the summer it has risen to 95+ degrees. I setup a shade over top and the temp only rises to around 90 in the day time. By contrast, my pool in the back yard which is all the way in ground, stays between 55 and 90, even though it is in the full sunlight all the time.

I got an electric heater - it is a 300 watt meant for inside aquariums. This past winter was the coldest in 10 years, it actually snowed one day here in Phoenix. The 300 watt heater was just barely able to keep the pond at 64 degrees thru the coldest parts. Figure if I hooked up a 2nd heater, it would keep the temp at just about whatever I wanted, if I wanted to spend the extra electricity. Sure was neat being able to keep the fish active in the winter -- last winter they all hybernated.

Backflushing
The shop vac back flushing works great. Only problem is I got tired of carrying buckets of backflush water and dumping them on my plants. So I rigged up a garden hose as my discharge line, and just drop a sump pump into the filter. It sucks up the debris in the bottom, I stir the bioballs as it goes and cleans in no time flat.

Ugly tubes, pipes & wires
I have read other people's websites where they go to great lengths to hide their pipes, wires and filters. I though I wouldn't mind seeing them because I enjoy mechanical stuff, and it would sort of symbolize that I built it myself. Well, I am getting tired of looking at the trash can, exposed PVC, and the wires. Furthermore, the UV sterilizer I bought ended up not being submersible, so I had to make the bracket that sits on the side, and holds it above the water. With a little more effort, I could have hidden all of the mechanical stuff.

Smoothing The Stucco
You can't see it very well, but the stucco on the sides of the pond walls is rather rough. I used a steel trowel to smooth it as best as I could, but you can see almost all of the swipe marks. Later I learned there are masonry sponges, basically a smooth plastic coating on a sponge, with a handle on it. These can make the stucco very smooth - I'll use it on the big pond.

Block VS Liner Pond
A hole in the ground with a plastic liner has got to be one of the easiest ways to make a pond, next to just using a hot tub shell or stock tank. With all of the time and money spent building the block pond, I wasn't sure if I would enjoy the block enough to justify it. Well I do !!! I really like the clean lines and shape of a block pond. It is just so much neater, and doesn't have all those annoying pleats. Also the sheer flat sides of a block pond make it deep near the edges, and that is important to help prevent predators from being able to attack your fish.

Flat Bottom VS Sloped
Many people have a sloped & specially contoured bottoms to channel the water to the bottom drains. My flat bottom was allowing gunk to accumulate, but to fix that I installed a jet to make a circular current, and a vortex seperator that pulls from the center. Combination of that and the fact that the fish flap away at the bottom keeps the muck moving and it gets pulled out. Later I heard this is called the "toilet bowl effect" where the water goes in a circle, and the debris collects in the center. I can see how a bowl shaped, sloped bottom would work a lot better -- but this dinky little pond is mostly for plants and goldfish, so I like having the flat bottom so it is easy to stack buckets of plants and rocks.

Depth Of Pond
Real koi enthusiasts have very deep ponds, like 4' deep or greater, even though they might not be that long and wide of a pond. This is to increase the volume of water they have without taking up that much square footage -- the more gallons you have, the more koi you can keep. Others have said that 24" is plenty deep for non-koi fish, as long as 16" is underground to stabalize the water temperature. The test pond is only 2 blocks deep, making it 16", and I can see that 24" would be great for sunfish, pond comets & similar sized fish. But I have turned to the dark side and now have koi, and fully understand the need for deeper water. Koi get big quick, and 24" is just not deep enough. For koi, they need atleast 3' of depth, 4' would really be a minimum comfortable depth, and great than that is nice to have.

Need a Hospital Tank
Any new fish that comes in from the wild really should be isolated for 2 weeks and treated for everything whether it has it or not. Had anchor worm come in with a fish, and it spread to my entire pond. I have a couple of small play pools to use, plus a spare stock tank for quarantine and treatment of fish.