marine tank gone cloudy

[nmonks]

Hello,

A friend of mine has asked for help from me, but such expertise as I have is with freshwater. So, I'm a bit out of my depth here...

She's recently set up a marine tank. 180 litres, has a built-in filter (Rio Compact H kind of thing) and an external Rena filter (can't remember the one, but rated for about 150% the volume of her tank). She's been guided by a very experienced and trustworthy retailer. Added lots of cured living rock, no sand yet, and just fish (damsels and so on).

There's no protein skimmer and just two regular lights in the hood.

The problem is that for the last month or so the water has turned very cloudy. It appears to be brownish, and when you watch the water it seems to billow as if the particles are not evenly distributed. There's not much algae on the glass or rock, and certainly nothing like blue-green algae.

Phosphates and nitrates are kept low using (a) removal resins and (b) by making water changes with reverse osmosis sea water.

To me, it sounds like she's doing things right, but I can't see why there is algae and/or silt in the water. Is this the marine version of new tank syndrome? Is there something I can recommend?

Many thanks,

Neale

PS. The fish are thriving, so it doesn't seem to be toxic in anyway, just ugly.

 

[Navarre]

It is possible that there is new silicate growth due to it being a new setup.. This happens in everyones tank and cannot be avoided. I even removed all the water and sand fro my old tank and used it as a biulding block for my larger system only to get the same silicates appear once again! (Even dust particals can carry enough silicates onthem to triger its growth in small measures.)

Whilst i would say that you are probably looking at silicate algae growth I would advise strongly in the purchase of a skimmer. As you have not mentioned that your friend is using a mud based filtration (which can be run skimerless) Skimmers take so much out of hte water that we cannot even test for and the colouration of hte water could well be down to water conditions in need of skimming.

Theere seems to be a heavy reliance on mechanical filtration and this is not that beneficial to the tank if its trying to use liverock as its maind source of filtration. WHen i realised just how powerful liverock truely was i removed all filtration medium from my externals and ran them constantly empty (i kept them running to increase flowrats and in case of emergencies i could add things inside the filter with ease to assist in recover etc.)

If none of the above help out then perhaps an invetment in an ozone unit (you would probably need a skimmer for this) will make your water crystal clear).


Most cloudy water however is caused by macterial blooms due to changing water conditions. If its not removed (through skimming or mineral mud) then its highly likely to have a knock on effect of raising nitrates and phosphates.

Lastly, just because phosphates dont register when you test for them doesnt mean they are not present in the system. Phosphates can be used up extremly fast and give artificially low readings. I was told once to test my water vey close to any algae growth for phosphates and i was amazed at the difference in phosphates to the rest of the tank.