I've done 3 water changes over the course of this week on my BC29 using R/O with Instant Ocean but the Cyano always grows in the center towards the front of the tank even after a water change. I sucked out all the sediment in the back chambers. I have a Sapphire skimmer, Purigen bag in the 1st chamber, Phos bag in the 2nd chamber, and a purigen bag with Chemi Pure Elite in the 3rd chamber with a Rio 6hf pump. If I adjust the flow onto the cyano it rearranges the sand. Not sure what else to do other than go crazy. Current stock is 1 saddleback, green BTA, zoas, xenia. I feed the clown every other day and only once during that day. No nitrates or phosphates show up when I test the water.

So I'm going to trest the R/O tonight that I get from my LFS.If it is high in phosphates how can I alleviate this problem? The LFS is the only place to get R/O from in Vermont. There are only two LFS in Vermont.

I guess if the RO from the LFS has phosphate you could try circulating it with a bag of phosphate remover. While we were on vacation my tank was overfed and I had cyano when we got home. I kept siphoning it out and changing water but it came back within a couple of days every time. I finally gave up trying to get rid of it using natural methods and used Red Slime Remover.

These 3 steps have worked for me:

Try adding another powerhead or shifting around existing powerheads or return nozzles to finesse your water turbulence or at least make better use of your overall water flow. Examine the areas where the cyano tends to collect and make sure there aren't any "dead zones" where the water looks still or food particles are settling instead of being kept in the water column.

Siphon out as much of the slime as you can. Airline tubing works pretty well for siphoning but if you have really thick mattes of cyano on your rocks/sand you might want to use something else like a turkey baster or something.

Temporarily cut your lighting period back. Keep the tank lit for only 4 or 5 hours a day for the next few days (corals and macroalgaes will be fine, cut the period back slowly if you have an anemone or any easily stressed livestock). After a few days gradually start increasing the period again by 30 minutes every 3 or 4 days until you get back to your original, preferred, lighting schedule. You'll probably see the cyano dwindle within just a couple days of cutting back the photoperiod but I've seen it come back if you skip the gradual increase and just jump back to running your lights for 12-13 hours a day. I think the gradual increase of the lighting period allows the other organisms in the tank that would normally use/consume the cyanobacteria a chance to catch up.

Increase flow, especially in the trouble areas.

Make sure you have enough scavengers and sand sifters.

Make sure your PH and KH is on the high side of the acceptable scale.

Reduce or eliminate the use of foods and additives that contain sucrose, glutcose, gel-binders, and EDTA.

Know exactly what is in your water prior to adding salt mix.

In regards to phosphates, hair algae and diatoms are more effected by phosphates then cyanobacteria. Phosphorus is part of natural seawater and a required trace element, however it does show up on many test kits as phosphates.

So I'm going to trest the R/O tonight that I get from my LFS.If it is high in phosphates how can I alleviate this problem? The LFS is the only place to get R/O from in Vermont. There are only two LFS in Vermont.

I would suggest that you purchase your own RO/DI unit and a TDS Meter to purify and test water. It will eventually cut down on the cost of driving out to purchase water from your local fish store and you can be sure that you follow the maintenance on it to keep nothing but 0.000 TDS reading aka PURE wate coming to you. It was honestly the best purchase that any Marine Aquarist can make and it is relatively cheap. :up:

I would suggest that you purchase your own RO/DI unit and a TDS Meter to purify and test water. It will eventually cut down on the cost of driving out to purchase water from your local fish store ...

If you're going to continue buying water (instead of splurging the $$$ for an RO/DI unit) I'm pretty sure you could find somewhere other than those two local LFS's to buy water from, check your local grocery or department store.


JayBeDriften, what product or process did you use to clear up the cyano outbreak you had last year?