THE PERILS OF CONCRETE PONDS FOR FISH & PLANTS
Biological filters are often under-designed (or flat-out non-existent) for concrete ponds, especially if they were not built with living ecosystems in mind. Oftentimes, a landscaper will build a "pond" for someone during a time when they're not considering adding life to it. Or the landscaper just doesn't ask about such things, because they're not a pond specialist, or they just don't care. Biological filters are homes for bacteria and zooplankton in which to live and convert poo (algae gold, but harmful to fish if too concentrated) into plant food. When the filter is under-built, it's much too small to house the required quantity of micro-organisms to convert the excrement load. It usually plugs up before it can even begin the conversion process! Every time you clean it, it reboots the conversion processing, starting over something that takes up to a week just to cycle and get started again. Very counterproductive.
If you've been trying to create an ecosystem in your concrete pond, and have been using bacteria and enzymes, you may forget and leave the living beneficial bacteria product outside, because using it is more convenient if it's right next to the pond. However, in the 100+ temps, that bacteria you are adding is now dead. It needs to be alive to do anything beneficial, which is coming out of dormancy, colonizing your bio media, and beginning the eating and conversion process.
After 20+ years in this business (since 2000), we can tell you we are certain that small concrete bowls of water containing aquatic critters producing ammonia-laden defecation in the water every day, and sporting little to no biological filters, are never, ever guaranteed to produce and maintain a stable, balanced, clear-water aquatic ecosystem. Every time a fish or turtle defecates, the water parameters change measurably. In fact, zoos have staff specifically tasked with complete water change-outs and cleanings, every week, on ponds with a bio-load that is greater than the regeneration zone or biological filtration to compensate.
We are happy to try and help with these pet tanks, but you'll need to be crystal clear about your expectations for it. If you wish to discuss this further, we would be happy to assess your situation and suggest a pond management program where we help you move forward with your existing pond on a weekly, bi-weekly, or monthly basis (depending on how much work you want to do yourself).
If you love the ponding hobby and would consider replacing your existing water feature with a beautiful, living, ecosystem pond, we do offer a clear water guarantee. Every single pond designed and built by The Pond Gnome in the last 20+ years came with a clear water guarantee. Please feel free to visit any of our public displays, or our office/showroom (by appointment) if you would like to see the difference for yourself.