Post
by Diana » Sat May 26, 2007 12:54 am
Hi, 2 Many Tanks.
I have a few ideas, and some thoughts. I do not know if these are linked to the deaths in your tank.
You were in the hospital when the first deaths happened? And the fish were not removed?
Decaying fish produce much more ammonia and use more oxygen decaying than when they were alive. Ammonia goes up, perhaps filling and overwhelming the ammonia removing crystals you use, and the small nitrifying bacteria population cannot grow fast enough, so ammonia spikes when you are not there to see it. Bacteria grows, fed by dead fish, and turns Ammonia into Nitrite. The bacteria responsible for turning Nitrite into Nitrate is slower growing, so the nitrite spike lingers until you get home from the hospital
pH in this tank was less than neutral when this happened.
Ammonia is in its less toxic form when the pH is acidic. At higher pH the ammonia is more toxic. You added baking soda to raise the pH. (in fact, raising the KH, which in turn raised the pH) Probably moved some of the ammonia (if any was left, I think there was) to the more toxic form. Not by much, but enough to bother the fish. pH drops in an aquarium that has organic matter accumulating somewhere. Often it is accompanied by high Nitrates.
You began water changes.
On the whole, this is the best thing you could have done. Removing the toxins from the water, the dead fish, and so on is the right thing to do. All the normal cautions apply, of course: New water needs to be similar to the tank water for temperature, GH, KH, salinity and pH. If your water needs to be aged for whatever reason, do that. This is so not only the fish (which can tolerate small changes) but also the nitrifying bacteria will not be shocked.
You saw a reading for Nitrites
Nitrates cause brown blood disease. This means that the blood cannot carry oxygen very well, and the fish suffer from lack of oxygen. (If I spell it right, google Methamglobinuria for more info) Adding Sodium Chloride can reduce the problem. Chloride prevents the Nitrite from crossing the gills and getting into the blood. As small a dose as 1 teaspoon of salt (sodium chloride) per 20 gallons is enough to help the fish. Water changes to reduce the Nitrite are required. Adding Prime can help, but do the water changes first so the Nitrite is as low as possible before adding salt and Prime. Continue testing, and repeat water changes as needed, re-dosing the salt to maintain the level of 1 teaspoon per 20 gallons. Salt can be aquarium salt, table salt, Kosher salt, pickling salt... Sodium Chloride is the active ingredient. It should be well dissolved in water before adding it to the tank.
You added Marine Salt to a tank with low pH, and no salt.
Part of the problem is the pH when Ammonia is present in the tank. Otherwise, changes in pH in and of themselves are not usually an issue, as long as these changes are within the fishes' normal range of tolerance. It is the other chemistry changes that often happen in conjunction with pH changes that can cause problems. Marine salt has a LOT of other minerals in it. Mixing it with fresh water raises the GH (General Hardness; Calcium, Magnesium) KH (Carbonates, at this pH) and in general the Total Dissolved Solids (TDS). This can be quite a problem for the fish. They are metabolically geared to handle fresh water, low TDS, pH somewhere close to neutral. They can handle a range of conditions, as long as the change happens slowly, but overnight is not slowly, in the case of this change. A fish already under stress is likely not maintaining its osmotic balance very well, and throwing it for a loop like this could be what pushed them over the edge. The Mollies and other Livebearers might have tolerated this event; they have evolved to handle hard, alkaline, even brackish water. The Clowns are not set up to handle it. While Clown Loaches can live in hard, alkaline water, they were probably acclimated to it much slower, like over a month or so. They are not brackish water fish. /i]
UGF, Ammonia removing crystals.
I do not like them, so take this part with a grain of salt. Marine salt, if you like.
UGF is NOT a FILTER. It is a way of hiding the dirt 'under the rug' where it decomposes. Ultimately it becomes a sort of fertilizer storehouse for plants. In the process a lot of decomposing happens. The unhappiest tanks I have kept have been aquariums with UGF set ups.
Ammonia removing crystals are starving your nitrifying bacteria. The population is low, because there is not much to feed on. When the crystals are full, the bacteria start to grow, but then you change the crystals, starving the bacteria. Net result is that when you need a boost in the bacteria population, there is such a small population, there is no cushion to fall back on.
Fish with slime coat problems are often reacting to water chemistry issues.
Slime coat is one way fish have that protects them from some of the changes in water chemistry, helps them to maintain their osmotic balance by reducing the amount of water that leaves or enters the fish through their skin. Salt is one stimulant to slime coat growth.
Restocking: I would remove the UGF from this tank, and the ammonia removing crystals. Depend on live plants and nitrifying bacteria to do the job. After so many ups and downs, give the tank a rest, let it stabilize over a month or so, get some plants growing, then start restocking. You can get the fish, but they go in a quarantine tank, anyway, not the main tank. By the time you are sure the new fish are disease and parasite free, the main tank will have had enough water changes to remove the salt and minerals, and will have shown stable readings for several weeks. Otherwise, do not trust it to keep the fish healthy.
Why does this tank show such swings in water chemistry when you clean the filter or do a water change?
Pure conjecture on my part, but I think you do not have a stable ecosystem established here. When there is some disruption, the change is affecting a large percent of the microorganisms, and they cannot stabilize the system because their population is too small. You are stirring up stuff that was becoming settled, and somewhat out of the water column, and there is not the reserves of bio-filter to handle the issues.
38 tanks, 2 ponds over 4000 liters of water to keep clean and fresh.
Happy fish keeping!