Cloudy Water/Bacterial Bloom ?

Jimbo · Nov 30, 2014

70 gallon SPS dominant set up for 3 1/2 years. I have always had crystal clear water but about 2 weeks ago I started developing a white haze in the water. It will not go away. Fish and coral all look good and seem to be unaffected. In fact the SPS seem even happier with excellent polyp extension and color.

All parameters are within range : Alk 9 dkh
Calcium 450
Magnesium 1380
Nitrate .75
PO4 0.03

I have been checking everything trying to find the cause of the cloudiness. I've run activated carbon, purigen, skimming wet. Still there is a slight white haze to the water.

I did notice the other day that my top-off reservoir ( 5 gallon acrylic box) was pretty dirty. I top off with 0 TDS RO/DI but I believe the water was contaminated due to the dirty reservoir ( I've never cleaned it in over 3 years ). I could see small pieces of debris in the water and it looked a little dirty. It's placed behind the stand so I never noticed it needed a cleaning.

Could this cause a bacterial bloom in the tank? I pulled it out yesterday and scrubbed it clean. Water still looks hazy today but if this is the cause maybe it may take a few days to clear?

Here's a couple of pics. Any advice or suggestions?

Randy Holmes-Farley · Nov 30, 2014

I doubt the top off water is the issue unless you dumped something into it.

A UV may eliminate it if it is bacteria, as might fine filters like a diatom filter.

As you noted, this is only an aesthetic concern. Waiting might be the easiest option.

You are not dosing organic carbon, are you?

Jimbo · Nov 30, 2014

No, not dosing carbon and I didn't dump anything into the top off water. That's what is confusing me, It seems like it's a bacterial bloom but I can't figure out the cause. I was actually hoping it was the cause because then I know I have corrected the issue and it would clear up shortly. It's going on 2 weeks now.

I don't have a UV but I do have a canister filter with a micron cartridge. Maybe running that for a bit would help clear the water?

I did recently siphon off a little of the top layer of my sandbed recently. It's a shallow sand bed , about 1" that I use a gravel vac on during weekly water changes. Could this have contributed to the bloom?

Randy Holmes-Farley · Dec 1, 2014

Yes, the canister will likely work, but may clog fairly fast. I'd try it.

Messing with the sand might have contributed.

Also, are you sure it is blown fine sand?

Jimbo · Dec 1, 2014

I have a very shallow sand bed and it's not the sugar size sand so Im pretty sure it's not blown sand. I do have a Randal's Goby and a Yellow Coris Wrass, but I have had them for years and never had an issue with them kicking up sand and clouding the water. I'll have to keep an eye out to see if the Goby started digging....

Thanks for your help, anything else I can check to see what's causing this? Can this eventually cause problems for my livestock?

Randy Holmes-Farley · Dec 1, 2014

If it is bacteria, it is because they are consuming organics in the water, which if you are not dosing organics, is likely from foods.

But unless you remove them somehow (skimming, etc.) they may stay in the water a long time.