Dealing with dust algae
 

Hi all,

I'm dealing with a dust algae issue that seems to be getting worse or at least steadily bad. This is just 2 days of buildup. The door in the background and windows surrounding do not let any sunlight hit the tank.

http://i6.photobucket.com/albums/y21...8/IMG_1105.jpg

This spot I let build up a bit to see, looks pretty brown.
http://i6.photobucket.com/albums/y21...8/IMG_1104.jpg

I've been googling and there seems to be no consistent advice to deal with this. The suggestions I've read range from lights out for 3 days straight to letting it grow for 3 weeks then remove with a big WC.

I'm only 4 months in on this tank, 1st SW tank. It's a 20g, "wild wild west" tank - no sump, no refugium. I have a hydor slim skim nano and eheim 350 surface skimmer.

Inverts:
- 14 snails (mix of cerith/astrea/margarita)
- fire shrimp
- rarely seen emerald crab
- 9 hermits

I do a 20-25% WC weekly. Temp is 77F, 8.3 PH, and always 1.025sg. I've cut back on feeding to 1x per day from 2-3x when I noticed last week nitrates were around 20ppm.

My coral (euphyllia/discosomas) and fish all look happy except for the torch with a mood that seems to change like I change my underwear. This could be because it was splitting from 1 skeleton to what is definitely 2 and maybe 3rd coming.

Do I just need to clean every other day and wait it out or is this not "new tank syndrome"? Should I consider that I've overstocked this 20g with my 4 fish (clown x2, chromis, blenny) and crew?

Thanks for the help.

What is your current NO3 and PO4?

Ditto.

Looks like diatom algae. Not a big worry, but a sign of overfeeding/under cleaning usually.

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)

Do you use RODI water or tap water?

No PO4 test kit :redface:, NO3 20ppm before WC and 5ppm after by the looks of it? Always hard to tell with the API kit and my eyes...

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.

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.

I agree with you 100%
Better skimming and possibly even a refugium is the way to go.

Once you get proper test kits for no3 po4 you can look into using red sea no3 p04 X or people call it nopox its bacteria that feeds on nitrates and phosphates, it also is used in many ways to eliminate algae and accelerate growth and colors of corals.
High accuracy test kits are a must.

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