Cyanobacteria problems...help

krschulz · #1 03-31-2008, 04:56 AM

Six months ago I started my 90 gallon tank and have (in the past 6 weeks) run into overgrowth of cyanobacteria. I have 4 Accela 1000 powerheads (256 gallons per hour) running constantly, a protein skimmer and T5 lights about 8 inches above the tank. The fish and corals are thriving but I always have cyanobacteria clumping my substrate together. I have removed most of the substrate, except the stuff I can't reach under my live rock; I have used erythromycin to knock it back (which it did for a couple of weeks); I have added the newer koralia 3 (856 gallons per hour) which has blown my substrate around and helps.
So, is this a flow problem that I should get rid of the Accela heads (they don't stick well)? Should I add another koralia turbo pump? What is the formula used to determine if my flow is adequate? Can you have too much flow?
Should my lights be lowered/heightened?
Am I overfeeding and getting this growth? Hard, green algae has covered the bottom glass of the tank and my snails are busy working at it. Do I cover the algae with substrate so it can't get light and hopefully dies off?
How do you clean under the live rock when you can't reach with the siphon/vaccuum? More flow?
All my chemicals are within range all the time except a bit low on potassium even with daily supplementing. Any help would be appreciated.

Reef_kid · #2 03-31-2008, 05:16 AM

cyanobacteria generaly grows when there is an excess of nutrients and organic waste.
treating a tank with erythomycin is good for killing bacteria however all that dead bacteria will provide more nutrients for bacteria to grow if its not removed. best way to do this is run active carbon after a treatment and increase skimming if possible.

there are also chemicals such as Poly-ox which will clump organics and waste together
which makes them easy to remove in filters.

increase flow and removing organic wastes are one of the best way to get rid of cyano.

saltaddict · #3 03-31-2008, 06:01 AM

I had a cyano problem for the last 3 months. I tried chemi-clean but it all came back after a couple weeks. I was told by a LFS to raise my Magnesium levels by dosing with Kent Tech M Magnesium supplement. I was skeptical but most all my cyano was gone within a week. Worked for me and worth a try. There is a thread on RC about high magnesium levels snuffing out nuisance algae. Just my 2 cents.

Your Cyano problem could also be related to high phosphates.

andresont · #4 03-31-2008, 06:50 AM

ZeoSnow combined/soaked with ZeoBak every two days worked for someone i know.

you can read about it in the ZEO guide where they explaine how to use ZeoSnow.

bv_reefer · #5 03-31-2008, 03:17 PM

cyano tends to be one of the ones that you think you demolished and it just pops out of no where, primarily while treatment try to restrict it to as little an area as possible so it doesn't become a nuisance to you're corals,inverts,etc. other than that you're flow is most likely on the lower side, and cyano usually grows easily where theres an abundance of nutrients, might have to cut back on coral feedings for a bit while treating.

ElGuappo · #6 03-31-2008, 04:12 PM

I had the excact same problem and added no chems to my tank all i did was cut my lighting time down to two 2 hour periods a day for a week and POOF gone. also flow was an issue for me so i added a korialia to hit my rock face. i slowley added tome to the LIGHTS ON until i was up to my normal amount of time. i did also leave and interuption in the middle (lights of for small period of time), hoping it would slow the photosynthisis.