Snais

[Kristyl60]

I purchased a 55 gallon tank from an individual and a Cascade filter system. I washed both thoroughly. When it came time to clean it, I noticed it had snails in it. I broke it down and cleaned it thorough again. After about a month I noticed it started to look like brown dirty water and had snails again plus small white worms swimming in the tank. My husband and I broke it down again and done another deep cleaning on it. We cleaned all decorations and gravel. Instead of using the Cascade filter, I purchased a new one, thinking maybe it was all caused from the used Cascade and that I didn'tget it cleaned enough. We got it set up and it looked awesome for about 5 days. The 6th day it started looking dirty again. I took filters out and they are brown, like mud has been run through them. I noticed white jellylike balls on the filters. Could this be snail eggs or something entirely different? I need help. I've had aquariums for 25 years and never had this problem.