Ammonia is deadly. It is primarily created through the fish’s gills, kidneys and intestinal waste. Decaying uneaten food, plant material and leaves also contribute to ammonia accumulations. Ammonia is reportedly the leading cause of fish stress, breaking down his immunity system and leading to bacterial disease. Measurable to high levels of ammonia is common in new ponds (and aquariums), over-stocked ponds and established ponds from heavy feeding in the spring prior to biological bacteria growth or from inadequate filtration. The only acceptable reading from an ammonia test is "0". If you get any reading of ammonia in your water you can do the following to correct the situation:
Temporary Fix: Do water change. Don’t forget to dechlor. Cut back or discontinue feeding. Add ammonia binders that convert the ammonia to a nontoxic stage. Add products such as zeolite or ammo-rocks.
Permanent Solution: Add an adequate filtration system. Reduce fish load. Clean filter and remove any debris in the pond. Give your biological system a boost with biobuilding products.
Nitrites
Nitrites create the first step in the nitrifying cycle and is second to ammonia in its toxicity to fish. Nitrosomonous bacteria converts ammonia to nitrites. Nitrite readings are normally seen as the nitrifying cycle is developing and can be present without an ammonia reading. The only acceptable reading from a nitrite test is "0". Should you get any readings you may try the following corrective action:
Do a water change. Don’t forget to declor. Discontinue feeding. Add non-iodized salt at 3 pounds per 100 gallons. Salt will help neutralize some of the affects of nitrite poisoning.
Nitrates
Nitrates are the last step in the nitrifying cycle. Nitrobacter bacteria converts the nitrites to nitrates. As a rule, nitrates are nontoxic to fish. High nitrate levels contribute to algae bloom. Basically, nitrates are fertilizers. Acceptable test readings are 200 to 300. If your water contains more nitrates than 300 ppm you should do the following corrective action:
Do a water change. Be sure to declor. Reduce feeding. Reduce fish load. Clean pond of any rotting leaves or debris. Add plants. Plants will consume a large amount of the nitrates.
pH
pH is the way water is determined to be acidic or alkaline. 7.0 is considered to be neutral. Koi and goldfish live quite comfortably in pH ranges of 6.8 to 8.0. The danger with pH is when rapid changes in pH occur, resulting in stress to your fish and, on many occasions, death. We call them pH spikes. Slight changes in a 24-hour period in pH is normal. Heavily planted systems will have more severe pH swings due to the plants giving off oxygen during the day and taking away oxygen at night and giving off carbon dioxide. Your lowest pH reading will be early in the morning. pH does affect the toxicity of ammonia. The higher the pH, the more toxic any measurable amount of ammonia will be to your fish. The perfect pH range for pond fish is 7.2 to 7.6. If the pH in your water is too high or too low or making those dangerous swings, you should take the following corrective actions:
Stabilize your water. Products are available that will hold your pH to 7.0 or 7.6. These products buffer or stabilize your water so that the increases and decreases are minute. Buffering or stabilizing your water also is referred to as "total alkalinity". Add crushed oyster shell or crushed coral. Stabilizing or buffering your pond water is a very important step in having a healthy fish environment. Total Alkalinity range, 120-180.
Hardness
Referred to as "total hardness", hardness is the measure of calcium and magnesium in the water. Water around Atlanta is soft, less than 50 ppm. The importance of hardness in pond water is that koi and goldfish hold their best coloring in moderate hardness, 50-150.
Products are available (such as calcium chloride) to increase the water’s hardness.
Water Changes
A 20% water change should be made at least every two weeks. Water changes reduce the level of toxins if present (ammonia, nitrites, nitrates), reduce the bacterial load (free-flowing bad bacteria) and reduces the amount of dissolved organic material. It also adds back some necessary carbonates and minerals.
Aeration
One of the most common problems with ponds is not enough aeration. Waterfalls add an esthetic value to your pond but are not really efficient aerators. Many pond owners do not like a noisy or gushing waterfall, therefore, a lot of aeration is missing. Consider adding a fountain or air pump and air stones.