Hi everyone, I have a 29 gallon tank that has been set up for about 4 years. I had 3 black telescoping goldfish (all were small and added a month ago), 8 neon tetras (had for over 9 months), and 1 Pleco (have had for about 5 months). All fish had been healthy. Two months ago I changed the gravel and all of the fish survived fine, the water still turns a little yellow a day or two after water changes though. One of the goldfish developed cloudy eyes so I added Melafix as per the instructions. (I already do 15% water changes w/ gravel vacuuming 1 or 2 times a week). Now, within 4 days all but one goldfish and the pleco were dead! I cannot figure out why and now the last goldfish is acting funny, he sits at the bottom in a corner, behind some artificial plants, until I open the hood. The pleco seems fine.
The water specs are as follows:
Ammonia = 0
Nitrates < 20
Nitrite = 0
pH = 7.6
Alkalinity = 300 (kinda high but I don't know how to fix it)
Hardness = 150
I feed one algae tablet per day for the pleco and give flakes, pellets, or occasionally bloodworms to the rest for food.
Except for the Hardness and alkalinity (which don't seem to be that big of a deal from what I have read) all of these parameters look like good water to me. I don't see that I have over-stocked the tank either. Since the deaths began, about two weeks, I have been doing 25% water changes w/ gravel vacuuming every other day but that still did not stop it. My only thought is that maybe my bio-wheel has run its course (about 3 years old) and it may be time for a new one but that does not seem likely to me.
Any suggestions that you guys have would be much appreciated because I am absolutely stumped. I do not want to add any new fish to the tank until the situation is resolved for fear of wasting money and fish.
The water specs are as follows:
Ammonia = 0
Nitrates < 20
Nitrite = 0
pH = 7.6
Alkalinity = 300 (kinda high but I don't know how to fix it)
Hardness = 150
I feed one algae tablet per day for the pleco and give flakes, pellets, or occasionally bloodworms to the rest for food.
Except for the Hardness and alkalinity (which don't seem to be that big of a deal from what I have read) all of these parameters look like good water to me. I don't see that I have over-stocked the tank either. Since the deaths began, about two weeks, I have been doing 25% water changes w/ gravel vacuuming every other day but that still did not stop it. My only thought is that maybe my bio-wheel has run its course (about 3 years old) and it may be time for a new one but that does not seem likely to me.
Any suggestions that you guys have would be much appreciated because I am absolutely stumped. I do not want to add any new fish to the tank until the situation is resolved for fear of wasting money and fish.