Cyanobacteria warfare -- a losing proposition?

Question

I am fighting a long a bloody war with cyanobacteria in my 20 gallon nanotank. I'm about out of options, things to try. Looking for new tactics.

Here's the story:

Prizm Pro skimmer (supposedly good to 300, but Bob Fenner says 55 -- anyway I have 20)
About 25 lbs live rock, well seasoned, good coralline growth.
One smallish emerald crab
One dottyback - pseudochromis diadema
Two yellow fin blue damsels - medium sized
Four smallish hermit crabs
One smallish bud of mushroom "coral" anemone

PH 8.2 -- Phosphate 6 ish -- Nitrate < 5 ppm -- Nitrite / Ammonium 0 -- 80 degrees -- 9 Alkalinity

Aragonite substrate. Diatom growth on tank walls. Assorted live rock hitchhikers.

I feed most of one cube frozen krill / shrimp, strained to remove phosphate. At same time, I drop two drops concentrated zooplankton mix into 8 ounce and reintroduce.

DAILY water change of about 3/4 gallon. Did a larger change of about 20% over the weekend.

Cyano still persistent. Help.

Murphy -- what's your glitch?

Answer 1

get a gerbil. Not only are they easy to take care of, but they also have multiple functions (if ya know what i mean)

Answer 2

Cyanobacteria typically assails new tanks (i.e., set up within the last several months)

But it can appear and persist in established tanks if the conditions are ideal (for it): high nitrate, high phosphate and low/no water circulation, etc.

Not sure if you have any powerheads for water circulation (you didn't mention if you have any), but you'll want to increase your water circulation and eliminate any 'dead spots'. Additionally, you'll want your nitrates as close to 0ppm as possible and maintain phosphates at 0.03ppm or below.

Answer 3

I have no good answer for you -- I just wanted to express sympathy. I had a similar problem in my 20 gallon micro for a long time before I gave up and sold off all the rock and my banded shrimp. Never did figure out a good solution. :(