used tank and constant problems?

[mikem691]

I have a 75 gallon that i picked up used about 1.5 years ago. they said it was resealed. I also have a 55 and 15 that i have no problems with. The 75 I am almost always fighting some sickness in and now im thinking they used the wrong sealant. Does any one know if that would cause problems with the health of the fish? My amo and trites are always 0 and trates under 20. Weekly 50% water changes. If it was me causing the problems I would think the other tanks would have problems also.
Thanks
Mike

 

[ole scratch]

Oh boy. There could be lots of causes. 1 could be the sealant used. Could be u brought in a fish that had a disease that is now in the substrate or on the decor. Did u thouroghly clean the aquarium before set up. How about cleaning the decor? Are u feeding a good brand of food? Is this particular tank located near an area in the house that might have pollutants like chemical cleaners or under an air vent? When having problems of this sort with no obvious explanation, u really have to look at the whole picture. Good luck.