New 125 gallon tank, lost 5 fish in 3 weeks

[ejarrett]

So I recently bought a used 125 gallon tank. Cleaned it up real nice with zero chemicals. Transferred majority of water from my 55 gallon tank (cycled) and still using the same cycled filter on my 55 so I know I have plenty of beneficial bacteria. I did add a lot more decorations, but dunked them in boiling water to kill any bacteria before adding them. My tank came with a 4 small cichlids. I lost three fish to a fungus and two fish from what I can only assume as aggression issues. My tank recently has become cloudy. Water parameters are near perfect as always with only about 20 nitrates. I do 25% water changes twice a week, and add SeaChem Safe to water when I do them. I just got done from treating the tank for 7 days with API Melafix. None of my other fish have any signs of fungus or fin rot. Am I safe? Or do I need to do more to prevent this from happening again? Tank has African Cichlids and a Pleco in it.

 

[Ch4rlie]

Water parameters are near perfect as always...

Near perfect?

 

[Byron]

As Ch4rlie was hinting at, we need to see the numbers for water tests. "Perfect" can have very different meanings. It would also help to know the species of the 4 small cichlids (those dead and the survivors), and did you have any fish in the existing tank that you moved over? In other words, which fish had fungus, which were aggressive, etc. While waiting for this data, I can offer a couple suggestions in general.

These decorations, were they from the place where you acquired this used tank and fish, or yours from the existing tank? They were probably covered in various bacteria, mostly good, and this can help establish new setups. If from another source, maybe a different approach.

There is nothing beneficial in old tank water, so using all fresh is generally preferable. What is in the old water is detrimental, though not dangerously so if it is your own tank. But the good nitrifying bacteria will not be in the water, it colonizes surfaces (like the filter media, substrate, wood, rock, decor, plants). The only time using the old water may be beneficial is if the parameters differ significantly, to avoid shock to the fish. And on the cloudiness, this is probably a bacterial bloom, very common in new tanks or those in which there has been significant "cleaning" of the filter, substrate, and sometimes water changes alone. Provided ammonia remains at zero, I wouldn't worry over the cloudiness, it should clear sooner or later.

On the Melafix, I am not a fan of these generic "cure all" sort of remedies, as they are often not effective and even more often may be detrimental. If a disease is present, the safest and most effective treatment is one relevant to the disease. If would help to know just what this "fungus" was; for example, you mention aggression, so was the "fungus" on the fins, suggesting it could be due to fin nipping?

Last point here, on the water changes. On a general routine basis, change more volume, closer to 50-60%, once weekly. This is actually more beneficial that two smaller changes, as the larger volume removes more "pollutants" at one go. This applies to all fish, but cichlids are especially aided with larger changes, as they have a real sensitivity to water conditions.

Byron.

 

[ejarrett]

Near perfect?

PH- 7.9
AM- Barely reading any
NI- 0
NA- 20-30

 

[ejarrett]

As Ch4rlie was hinting at, we need to see the numbers for water tests. "Perfect" can have very different meanings. It would also help to know the species of the 4 small cichlids (those dead and the survivors), and did you have any fish in the existing tank that you moved over? In other words, which fish had fungus, which were aggressive, etc. While waiting for this data, I can offer a couple suggestions in general.

These decorations, were they from the place where you acquired this used tank and fish, or yours from the existing tank? They were probably covered in various bacteria, mostly good, and this can help establish new setups. If from another source, maybe a different approach.

There is nothing beneficial in old tank water, so using all fresh is generally preferable. What is in the old water is detrimental, though not dangerously so if it is your own tank. But the good nitrifying bacteria will not be in the water, it colonizes surfaces (like the filter media, substrate, wood, rock, decor, plants). The only time using the old water may be beneficial is if the parameters differ significantly, to avoid shock to the fish. And on the cloudiness, this is probably a bacterial bloom, very common in new tanks or those in which there has been significant "cleaning" of the filter, substrate, and sometimes water changes alone. Provided ammonia remains at zero, I wouldn't worry over the cloudiness, it should clear sooner or later.

On the Melafix, I am not a fan of these generic "cure all" sort of remedies, as they are often not effective and even more often may be detrimental. If a disease is present, the safest and most effective treatment is one relevant to the disease. If would help to know just what this "fungus" was; for example, you mention aggression, so was the "fungus" on the fins, suggesting it could be due to fin nipping?

Last point here, on the water changes. On a general routine basis, change more volume, closer to 50-60%, once weekly. This is actually more beneficial that two smaller changes, as the larger volume removes more "pollutants" at one go. This applies to all fish, but cichlids are especially aided with larger changes, as they have a real sensitivity to water conditions.

Byron.

I did add some decorations from the new aquarium, but I did boil them to avoid any harmful bacteria, as it was clear the previous owner didn't care about their fish. The fish I did receive were small Pseudotropheus elongatus. My filter was perfectly cycled so I did not mess with it, and I used most of the substrate and decorations from previous tank. I believe there was some fin nipping going on, but there was definitely a fungus that two of fish got and died from so I treated the tank and isolated them. So I think im in the clear. I added carbon to clean out the medicine along with a 50% water change. The fins that were the result of fin nipping have grown back nicely, and I don't see any signs of a fungus, but my water is cloudy which isn't normal for my tank. I usually have crystal clear water.

 

[Ch4rlie]

Sounds as if you have had a spike, though not conclusive about that at this time.

Main clue being the cloudy water, this is usually indicative of a bacterial bloom. Normally cloudy water is seen in new tank set ups while the cycle process is starting.

Bacterial bloom should not have any affects on your stocking, just a little unsightly having cloudy water is all. These blooms will go once the tank settles and becomes more established.

I'd suggest keeping a close eye on your water parameters and doing any water changes if you see any spikes in ammonia or nitrite at or above 0.5ppm. Most healthy fish will cope with 0.25ppm ammonia for a short length of time.

I agree with Byron re the melafix or pimafix types of meds easily found in most LFS, these tends to be a very weak antibiotic type of meds that will not do much once any disease settles in your stocking/tank. I am of the opinion that good clean water changes will do more good than adding these meds. Remember adding meds or chemicals will go into ALL your tank inhabitants and sometimes this is not a good thing as this can stress out healthy bodies or can have detrimental effects.

So only treat meds once you are fairly certain of diagnosis and using the right meds of course is paramount.

 

[Byron]

I concur with Ch4rlie.

You didn't say what other fish you had, if any, so I can only mention that Pseudotropheus elongatus is one of the most highly aggressive of the mbuna from the rift lakes. Not knowing you level of experience, or knowledge of cichlids, I won't get into specifics, but these are certainly not "community" fish in the sense that they can be combined with anything other than rift lake fish, if carefully considered.

Nitrate at 20-30 is high. The larger water changes I mentioned previously should help lower these (unless nitrate is in the source water, another issue entirely). Cichlids are known to have issues with nitrates above 20 ppm over time. Malawi Bloat and Hole in the Head have both now been suggested as linked to nitrate.

Byron.