Greenish Brown Algae

[Nate]

OK, so I setup a 40 gallon breeder as a stand alone frag tank with a sump/refuge about 4 months ago. About a month into cycling I had a bryopsis and hair algae problem. So I started treating with Kent Tech M and successfully raised the mag level up to around 1900 ppm. However, over the past couple weeks a new kind of algae has started to pop up and it is now covering almost everything. I have scraped it off the glass only to have it come back in a few days. This new algae is a greenish brown color and is literally on everything: the tank walls, the eggcrate racks, and the frag discs. The tank is currently stocked with a bunch of frags, mainly sps.

 

So here is the situation. Ammonia=0 , Nitrites=0 , Ph=8.2 , Nitrates=0 , Calcium=450ppm , Mag=1900ppm. I have the 40 gallon paired with a 30 gallon sump. The filtration includes filter pads, 1 gallon of bio balls, 25 lbs of live rock, a couple hand fulls of chateo, protein skimmer, and a UV sterilizer. The light is a 10k 250w metal halide pendant fixture. I use RO/DI water for top offs but have not done a water change in a month or so because I was trying to get the mag levels up. There are no fish in the tank. I put a couple snails in there but they can't seem to keep up. The flow is 1200 gph for filtration and 800 gph from powerheads. The bryopsis and hair algae seems to have died off and I was getting ready for a water change when I thought I should get some advise first. Any thoughts??

 

Here are some pictures.

 

 

 

[zygote2k]

those don't look like sps frags to me.

the algae looks like diatoms.

[Nate]

those don't look like sps frags to me.

the algae looks like diatoms.

 

Yeah non of the sps are in the pics but I assure you this tank is sps dominated. I also was thinking that it was diatoms....

[dschflier]

I agree with zygote. What are your phosphates? To me it doesn't look that bad. I would get rid of the filter pads and bio balls. I would add more macro if you dont have much to compete with the algea growing. I would add carbon and GFO as well as a lawnmower blennie and more snails. I would also increase water changes for a couple of months while again scrapping off the algea. Starving it should slow it down and if you have the blennie and snails helping out I think you should be able to get rid of it.

 

Having no fish you should be able to keep the bio load down to a minimum. I would think using the above mentioned ideas would work. Just my 2cents

[Mich]

Check phosphates and silicates. Do you have a TDS meter on your RO unit? You might need to change your membrane or catridges? Usually diatoms preceed bryopsis in a new system's sequence of algal succession.

 

Also, I'd reccomend adding about a dozen astrea snails. Usually if you have a persistent film of any type of micro algae it's due to the presence of some form of decay or leeching. Excess nutrients that are being produced are assimilated by the micro algea at a rate equal to that at which they're being introduced into the system. This is why tests for these nutrients usually prove negative. Try to maintain a population snails that can keep up with your rate of nutrient import and microalgal growth. Some snail waste will contribute to the growth of more microalgae, but a fair amount of it will also become skimmate or be utilized by the chaeto in your sump. What micro algae does persist will keep your snails from starving to death. Add more snails as needed until you find a balance.

[zygote2k]

Dump the bioballs, filter pads, etc. Add carbon, skip the GFO (not needed), get some snails, and above all else- do water changes on a weekly basis.

[dschflier]

I have to disagree with zygoteck this time. Just my opinion but I dont see why you would feel carbon is necessary and not GFO. If your opinion is to go all natural and try that way I could see your point. Carbon will remove organic compounds which will reduce the amount of food in the water and GFO will lower Phosphates another major food source.

 

This is the way I always attack the problem. First I always think of what the objective is. In my mind it is to remove the unwanted algae. It doesn't have to be completely gone but completely under control. When I get to this point I then just maintain what I have accomplished.

 

The way I attack the problem is from every front I can think of.

1) I make sure my RO/DI filters are still good

2) I did 30% water changes for 2 weeks and then I went to 20% until I got the problem under control. The % change just worked for me. I am not suggesting this amount is what you need to do.

3) I started using 1 cup of GFO per 100 gallons and 2 cups of carbon per 100 gallons of water. I also changed the media every 3 weeks for about 4 months. I still use a similar amount of media now but change it out about once every 2 months.

4) I then started scrubbing any off I could find.

5) I began dosing Kalk which binds more of the Phosphates.

6) I also reduced my rock work substantially and tried to have few dead spots.

 

I figured this would starve the algae. In 2 months I noticed much of my hair algae turning white and some falling off. Some of my macro was also turning white or translucent. I did all this for about 4 months. This worked for me. It didn't happen over night and I sill believe certain fish and a bunch of snails do an excellent job. When dealing with a closed system I believe using all the tools that have shown to work is almost a must.

[Nate]

Thanks to everyone for throwing in their 2 cents. My TDS meter on the RO/DI is reading zero. I think what I will do is start by doing a water change and adding a lot more chateo. I will also get some snails. I don't think I need to add carbon or GFO because I will now be keeping up with a weekly 20% water change. I am not going to remove the filter pads or bioballs because I don't want to have a nitrite or ammonia issue. Instead of removing the media that is creating the nitrates, I will add a ton of macro algae to take up the nitrates. I hope this works. I don't want to see hair algae or bryopsis pop back when I dilute my magnesium levels with water changes.

Edited May 4, 2009 by Nate

[overklok]

Ditch the bio balls, nothing but nitrate factories. Let your rock do the filtering.