Reverse Osmosis? will it really help getting rid of filamentous Green Algae?

[Drewkin]

Hi Guys, Drewkin Here,
I'm as green as the Algae that has infested my tank as we speak, Ive been using filtered tapwater for a good few months now, here in the UK the Tapwater is generally OK, depending on where you live of course, the only real problem is Phosphate levels which are difficult to measure even with test kits.

The Tank is about 15 months Old and all inhabitants get on well.

Ive got a 200 litre tank with about 10 Kgs of Live Rock and around 50Kgs of Base rock, (not Tufa). 3 Green Chromis, 1 Regal Tang, a Six Line Wrasse, and 2 True Percula Clowns, rucks of red and black legged crabs, and turbo snails, a featherduster worm, and some mushroom polyps in there.

So the question is....apart from regular maintenance is the R/O water going to dramatically cut the level of phosphate enough to cause the algea to begin dissapear, Ive tried feeding less, reducing light levels ( Oh yea I forgot 2 x150w metal halides and 2 blue actinic) etc etc and wondered if the those with more experience could help a newbie out?

Ph 8.2
Am 0.1mg/l
No2 0.1 mg/l
No3 0.25mg/l
PO4 around 0.5 to 1
Sio4 Nil.

[bigjohn]

Hi Drewkin,

I also used filtered tapwater in my system for the first 2 years I had it set up. I was skeptical about the affect of trace amount of phosphates and silicates that were introduced to my system, and their ability to stimulate algae growth. I started using RO water about 6 months ago and the difference has been noticeable. I stop short of using the word dramatic, but I feed my tank generously, and I have increased my lighting duration. The algae still grows, but it is noticeably slower. I have not yet purchased an RO/DI unit, but it is on my list of things to do.

Hopefully, you have a convenient source where you can purchase RO/DI water. My suggestion is to try a 15% water change using RO/DI water, and use RO/DI for your topoff for 2 months. If you don't notice an improvement, go back to your tap water.

[PaintGuru]

I definitely would purchase an RO unit (which aren't that expensive anymore for a simple 25 GPD unit). And dont trust getting your RO water from the grocery store or something, because that isnt necessarily free of contaminants either. The reason I say this is during college I had a 20 gal reef and my water supply was an RO station at a local grocery store. Well I had major problems with cyno and green hair and I couldnt get rid of them if I tried. Once I moved and picked up my own unit, it "magically" disappeard and was never heard from again. I have a feeling the stations are not maintained very well and if you are really having problems with algae, a RO unit of your very own would probably help. I tried everything from reduced feedings to shortened light cycles and none of it did any good until I got the new RO unit. Just my 2 cents.

[Casey]

Get an ro/di filter It will really help you out it is worth the money for sure.

[mikeMersot]

RO/DI will certainly help reduce your nutrient inflow, and thus help to strangle out the micoralgae. I cant help but notice that your NH3 and NO2 levels are non-zero. I hope this is only the result of a minicycle or a test fluke or something as even a small amount of ammoia and nitrite can be toxic, especially over long periods.