Hi everyone!
I am joining this forum in desperation! I am totally stressed out about my 55 gallon which I had to totally break down after 17 years of regularly replacing my filter and 1/3 of the water—due to an algae issue.
In the past 3 months I have now replaced EVERYTHING in my tank and am now down to (about 5 fish), gravel and water and still –each time my tank water get to about 30 days old IT STARTS TO CLOUD UP, making my fish ill. (My grey gouramis, and catfish are my only survivors.)
Any and all suggestions considered and greatly appreciated.

Signed,
About ready to switch over to a Terrarium

Two things come to mind: #1, are you allowing the tank to establish a nitrogen cycle BEFORE you add the fish to it when you are resetting it? If not, it's not the cloudiness that's killing your fish - it's the elevated levels of ammonia and/or nitrite. A tank can take up to several months to cycle, if it's a big tank and there aren't many fish.
#2, is your tap water high in nitrates and/or phosphates? If so, that might be the cause of a cyno outbreak, which would make life hard for your fish for sure.

Do you have a water test kit? If so, what are the water parameters? If not, take the water in your tank to a local pet store and have them test it and GET THE PARAMETERS, don't just let them say "oh, your water is fine", because many pet store clerks DON'T KNOW WHAT THEY'RE TALKING ABOUT!!!

In addition, if you didn't already know about the Aquarium Nitrogen Cycle (Google it for more info), here's a good link:
The Aquarium Nitrogen Cycle

Hope this helps, and welcome to the gang!

__________________
Officially fishless until after the move....tune in later for details!

kill the lights and stop adding food until the tank clears.

If you don't have plants then go planted.


my .02

__________________
fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

Lights won't make a difference unless the cloudiness is green. Have you tested the water to see what is going on at all during this time?