GFO and SPS

[Lockhartia]

So I'm fairly new to SPS, but so far have been having good luck (knocking on wood as I type that). I have a 60ga cube (2'x2'x2') that is a 50/50 mix of LPS/SPS. I consolodated several tanks into this one over a year ago, and at the end of the summer completely re-did the rockwork to get ready for the SPS transition.

Since doing so, I have had a small outbreak of some type of algea. I'm hesitant to say it's green hair, as it doesn't behave as such. Also in a wierd little twist it's only in ONE spot in the tank, the upper right corner. I have replaced light bulbs, switched light bulbs, redirected flow, everything. It's only growing on one of the rocks that had originally been mostly buried in the sandbed. I have scrubbed it, but it comes back. It feels almost like diatoms, but is not. It's slimy and won't pull off easily, but looks like hair algea, and it is driving me INSANE.

The water tests 0 for phosphates from an API test kit. Other paramaters are:

ph: 8.2
mag: 1375
calc: 460
Alk: 2.5 meq/l/ 7-8dkh(yes I know this is low, but also no corals have shown any sign of being unhappy with this lower alk and are growing like weeds! I plan on slooowly bumping it up)
spec. gravity 1.025

So the roundabout way to ask my question: I have a dual chamber carbon/gfo unit that has been offline for a while. I've heard negative things about GFO and sps/clams (I have 10 clams) so I'm really nervous to fire it up for one spot of algea that's just unsightly, not actually hurting anything. Should I just leave things be or turn on the unit? Anything I should do/know if I do turn it on? Any brand of gfo better than another?

I do have an aglea blenny who is very fat and round, but he hasn't been able to really do anything about this spot. Most of the tank is filled with small little gobies and one flasher wrasse. Filtration is done via sump filled with chaeto/live rock and an Reef Octopus NWB200 skimmer (it's the older version). And yes I use RO/DI water and I just replaced the membranes (ALL OF THEM) two months ago and testing at > .01.

Lighting is 10x24watts of T5s from twin Aquactinics TX5s. The bulbs were replaced in mid September.

Any advice/thoughs would be greatly appreciated. The algea's not spreading anywhere, but it's not going away either. So far all the SPS have been growing, laying down nice bases and the birdsnest's are growing new tips. Colors on the sps are PERFECT, bright and vivid, and they have great polyp extension. I had one mishap with a wooly acro that blew up in a night, but that's it. Thank you!

 

[wdflier]

I'm no expert, but it sounds like you have found a happy medium with your corals and are doing really good, without the GFO. IMO I would rather increase my critters/clean up crew (crabs n snails) to take care of a small patch of algae that is not growing or spreading.....just my two cents

 

[Aqualund]

What are your phosphate and Nitrate levels reading (the only test kit i trust is the red sea pro kits or a photometer)? Whats the Phosphate level of your RO/DI Effluent? Based on the answers to those...do you even need to run GFO? Also, remember that algae may be using all the Phosphates and Nitrates in your water column making you're water read 0 but being just enough to keep the algae alive.

Im running GFO and bio pellets in two chambers in my SPS/LPS tank with no "issues" and have no complaints. However, if you wanna kill that piece of hair algae you can use hydrogen peroxide dip if you can. Im not sure if you can pull the piece out that you're referring to.

But like he said...sounds like you got a good balance, I would leave it alone and just scrape it off

 

[MammothReefer]

If you are getting good growth, and good colour I wouldn't mess with it. The only problem with gfo that I've seen is it can reduce alk so you need to compensate for it if you go that route. I'm running GFO/Carbon as I need it to keeps things down. I've thought about taking it off and watching what my phosphates do, and I've also thought about putting biopellets back on. I'm getting between 0 and .07 on my hanna checker, and I typically just replace it when I see a consent ride on phosphate above .03-.04.

However with that said I personally believe the less amount of equipment, or products you can run and have your tank thrive the better off you are. If you don't need it don't add. It just complicate things.

I would just trim out the aglea, see if you blenny can get the rest and call it good if it keeps up or if you get a more accurate test kit and find can benefit from gfo, I wouldn't hesitate to run it just start off slow and make sure to adjust your alk accordingly... ...you could also just try cutting back feeding a little bit and doing a couple water changes if you are on the edge, or just toss some cheato in your sump and hope that takes up enough nutrients that it starves out the algea in the display.