Dealing with dust algae

[Frogger]

Originally Posted by gregzz4

To elaborate on Myka's post ...

I find I get your kind of dust algae when my NO3 and PO4 are out of balance.
A recommended 'ideal' balance is around 1ppm NO3 and 0.03ppm PO4.

I never used to worry about these #'s, but found I was having issues with my PO4 being high and my NO3 always being 0.
After reading a post from ryanerickson about boosting Nitrates, I looked into it further. Then I proceeded to damage my corals by adding Nitrogen at a level too high and too fast, which caused my PO4 to crash.

I'd recommend you try adding a 'very small' amount of an NO3 source, such as Seachem's Nitrogen, and see what happens, per se.
Start with about 20% of their bottle dosage every other day, and test/monitor things.
Test daily to track what levels of Nitrogen addition affect your PO4 without completely reducing it.

DO NOT add too much Nitrogen quickly if you have corals. This will guarantee a crash in your PO4 level and result in some/all coral deaths.

I can confirm from Greggs experience that a Phosphate crash is really bad and it happens quickly. Before adding nitrates find out what your nitrates and phosphates are. Must use a quality nitrate test kit, Salifert and API donot measures low levels of Nitrate and should only be used for levels above 2ppm. Red Sea Pro has been the best for me, I have tried most of them except the low range Hach. (price)

[Reef-Geek]

Do you use RODI water or tap water?

[604reefer]

Originally Posted by Frogger

I can confirm from Greggs experience that a Phosphate crash is really bad and it happens quickly. Before adding nitrates find out what your nitrates and phosphates are. Must use a quality nitrate test kit, Salifert and API donot measures low levels of Nitrate and should only be used for levels above 2ppm. Red Sea Pro has been the best for me, I have tried most of them except the low range Hach. (price)

I'll order a red sea kit from reef supplies I think. The two in one, NO3/PO4? Should also get a good alk/cal kit.

[whatcaneyedo]

Maybe I'm becoming old school but boosting Nitrate when its already around 20ppm to reduce phosphate which is currently unknown as a solution against film algae sounds horrifying. Whatever happened to suggesting a skimmer upgrade? A quality adequately sized skimmer/sump will do an excellent job of removing organic waste before it has the chance to break down into nitrate. Fish poop + uneaten food -> Ammonia -> Nitrite -> Nitrate. Skim out more Fish poop and uneaten food = less Nitrate with no risk of a chemical overdose, easier ongoing maintenance and stability.

When you know what your phosphate level is and if you decide that it needs to be lowered there are easy to use products like PhosDown and GFO that can do that reasonably safely and economically.