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I have some 'suspected' cyanobacteria in my 29 for a couple weeks now. I've increased waterflow and have let the nitrates climb a bit. Nitrates are 20 right now, just tested. What's the desired nitrate level to combat the cyano ? Thanks !


The Amazon Nut...

I'm certainly no "rocket surgeon" when it comes to this, but it seems that Cyano likes it when the nitrogen to phosphate ratio is low.

I'm guessing in this case that upping the nitrate levels would somewhat "rebalance" that equation. The line of thinking seems to be that a higher nitrogen to phosphate ratio would encourage plant and true algae growth, which would then out-compete the Cyano for nutrients.

This is from the Krib:

"Blue-green algae can fix atmospheric nitrogen, so their dominance becomes favored at LOW nitrogen levels, not high. As I posted earlier, blue-greens are favored when the N : P ratio becomes low (less than 16:1), while the growth of diatoms and green algae are favored at high N : P levels. Thus, when P is in abundance and N is low, you can generally expect an outbreak of blue-green algae."
( http://www.thekrib.com/Plants/Algae/cyanobacteria.html )

If this is the case, then the desired nitrate levels would be based on what the phosphate levels are at, but I'd be very surprised if 20 ppm wasn't covering it.

Regards,
Dex



Last edited by dextroze at 10-Oct-2004 23:24

Last edited by dextroze at 10-Oct-2004 23:24

I've ben able to reduce to the point of almost eliminating cyno from my planted tanks by keeping the nitrates in the 20ppm range. I've found increased water movement helps as well (use a powerhead rather than an airstone to reduce CO2 loss).

^_^
*Proud member of the Committee for Sig Line Restoration*

I try to keep my nitrates between 15ppm and 30ppm, and I never see BGA.

I've read somewhere that 10+ppm of nitrates will help get rid of BGA.

Thanks all ! It's been 20ppm for about a week now I think. I'll keep the nitrates at about 20 - 25 for awhile and see how it goes ! Also thinking of taking some of the rock / cave decor out, scrub and boil etc..

The Amazon Nut...

The more you can remove by hand the better you'll be able to control it

^_^
*Proud member of the Committee for Sig Line Restoration*