Dealing with cloudy water

[C. Andrew Nelson]

A friend of mine has a saltwater tank that has been set-up and running for months. The water was crystal clear until he eventually added fish and corals to it. Now it's cloudy and remains cloudy no matter what he does. The scaping materials are simply sand and live rock. The fish and corals appear to be thriving, but the cloudiness is driving him crazy.

Anyone have any clues as to what could be causing the cloudy water? I will get more info from him regarding how he has it stocked, what he's feeding the fish, and what sort of filtration he's using. He wants to know if using carbon in the filter would help or if he should try using a product like Seachem's Clarity. (I've already told him he should find the cause before trying to treat the symptoms.) Any help is greatly appreciated.

[Diana]

Couple of different things can contribute to cloudy water.
Note that I only do fresh water, but some of these are possible in any set up.

1) Fish stirring the substrate, bringing up debris or dust from fish waste, or powdered parts of the substrate (very common with play sand, peat moss and similar dusty substrates).

2) Chemical problem, for example ammonia or other issue. First thing I do when I see the water has a problem is to run all the tests I have.

3) Minerals or pH adjusters are not fully dissolved. I know when I made water for my brackish set ups the salt & mineral blend I used took a while to dissolve (I made it up in a garbage can with a small pump to circulate it), and adding Seachem Equilibrium to create a high GH fresh water tank also made the water cloudy until the minerals dissolved.

4) Someone in the house adds something you are not aware of (I have heard of everything from the whole new can of fish food to cheerios to jello and more).

5) The beginnings of green water algae. I do not know if this grows in marine set ups. In fresh water it starts off with cloudy water, not really looking green, more grey until the population grows. You can tell if it is the early stages by looking at some water in a clean white cup or filtering it through new polyester floss. It will show up green against these white backgrounds.

Definitely finding the cause is the first step in dealing with it.

[Hurriken]

Dianna, your response should be a sticky! Good work.

[Diana]

If anything should be added, or reworded, go ahead, or let me know and I will do it. Then it can be stickied.

[ScottFish]

That's why she is called our "Aquapedia Mentor."

[Hurriken]

Like you said it could be applied to any water quality issue.

[C. Andrew Nelson]

I wholeheartedly agree. It needs to be stickied. That was a brilliant answer, Diana. I made my friend read it. Twice!

[Diana]

I have made a couple of minor changes in the post above. If you want to sticky it, go for it.