Algae Problems

[MACH5]

Hello all.
I have been battling an algae problem (it looks to be cyano) for almost a year! I have tried several strategies to get rid of it but nothing seems to effectively eliminate it completely. Just recently (2 months ago) I added a po4 reactor which helped to control it but not eliminate it. I need advice as to what could be the problem and how to stop it. It seems at this point, however, that the algae has not been a problem with my acros and other sps. My water params are as follows:

Temp 79F
Ph 8-8.1
Sg 1.025
Dkh 8.5 (SALIFERT)
Ca 450 (SALIFERT)
Mag 1380 (SALIFERT)
Po4 undetectable (SALIFERT)
No3 0.2 (SALIFERT)
Orp 400mvs
Salt TMp (IO was used 5 months ago)

Please check the pics below and let me know what you think. I very much appreciate any input. BTW I feed my 3 fish (90 gl. system total) frozen foods once a day and I perform 5% (if not more) WCs weekly.

[jun_celis]

Looks like you have a lot of flow so it's not the issue. You might have to rearrange your powerheads.

[MACH5]

What's interesting is that this stuff is growing well on areas of the sand that get quite a bit of water movement. Sand particles moving about these areas. The algae however eventually seems to bind the grains of sand into a compacted thin layer. I have tried to syphon these layers out but comes back after some time.

[CeeGee]

This is probably a really dumb question but are you using RO/Di water? That looks like the algae I used to get on my FO tanks that I used tap water on.

[MACH5]

That's ok CeeGee. Yes I use a 5 stage RO/DI... running 2 DI chambers in sequence.

[cutegecko3]

im not for sure but i think cyano feeds on nitrogen not phosphate.thats why you have cyano and no hair algae.

[ipiniowa]

I have never seen green cyano. Cyano is normally dark red or brownish.

[MACH5]

Ipiniowa: Yes... but I believe that some strains can also come in green as well.

Cutegecko3: That's what I had observed. There is absolutely NO hair algae in my system... anywhere! I'm not sure either if cyano feeds on just NO3, but at a level of .2 I would think that's not high enough to pose a problem.

One thing is for sure... it's driving me nuts!!!!

[Saldarya]

Another easy question, but, are you rinsing the frozen foods before putting in the tank? You seem to have a handle on things, but sometimes it the little things....

[MACH5]

Yes, the food is rinsed prior to feeding. I agree... little details are just as important.

[drock59]

What is your photoperiod?

[MACH5]

12 hrs actinics. 6.5 hrs halides.