brown cyano/algae battle

burtbollinger · Sep 14, 2017

Hey there, I have a Red Sea Reefer 170 (@40 gallon) that is 9 months old. 25 lbs of Walt Smith 2.1 rock and a marinepure plate. Running a Curve 5 skimmer and recently an Avast Spyglass with 1/2 cup GFO. Also passively running a bag of ROX carbon in the sump. Filter sock changed every 3-4 days. Video for reference...brown algae is NOT visible too much here:

Nitrates - 5-7
Alk - 8.7-9.0
Cal - 470
Mag - 1440
Phosphates undetectable on basic Hanna.
Fritz RPM salt....8 gallons a week water change
O TDS RO/DI water out of new unit.
2 Clownfish, 1 Royal Gramma - fed 1 fingernail sized bit of LRS Reef Frenzy Nano daily.
Nanobox Duo light - 80 blues, 20 whites
Chalice frags are spot fed Reef Chili 1x per week

I was and still get a covering of brown hairlike algae/cyano? on my rocks and sandbed. It blows and brushes off but it is annoying. It was really bad until I stopped dosing Red Sea Reef Energy, cut back on Reef Chili and I added a few more CUC members...Currently I have about 8 cerith snails...3 narrsissus snails and a handful of hermits.

Adding more snails has helped keep the rocks clean, as has adding a GFO reactor and Purigen bag....but I still get more than a dusting of this brown stuff on my sand after a few days.

I have lowered my whites quite a bit and lean more blue now....

Lately, I have been sucking out sand and replacing with rinsed clean sand...but it too gets dusted brown with this hairlike brown stuff after a few days. At this point, I'm fairly sure its bacterial.

I was thinking about adding more snails that prowl the sandbed...continuing to suck out offending brown sand, and keep up on water changes...also keep on top of replacing GFO in the reactor. Is there anything else I should be doing? Again the tank is 9 months old...and still ZERO coraline algae. Could I still just be feeling the growing pains of a newer tank?

CodyRVA · Sep 14, 2017

Sounds like just a tad high on the nutrients. Try changing your socks more often or cut back on the food/dosing. I would not add any more CUC members; once you get the issue under control, they will likely starve out. I run ULN and my sand still needs stirred or turned over 2-3 times a week to maintain the "white pristine" look. Make small changes and observe, don't change too much at once. Be careful with GFO, a little goes a long way.

In regards to the coralline, do any of your frags or snail shells have any coralline on them? This is an easy, safer, method as apposed to buying live rock.

burtbollinger · Sep 14, 2017

what sort of stuff appears on your sand? can you describer your stir/turn over approach? I have recently been scared me stirring it was the issue

I had been in the habit of stirring once a week or so with a long stick.

CodyRVA · Sep 14, 2017

burtbollinger said:
what sort of stuff appears on your sand? can you describer your stir/turn over approach? I have recently been scared me stirring it was the issue I had been in the habit of stirring once a week or so with a long stick.

Basically like a faint brown... something? Hard to describe, but turning my sand on a regular basis makes a world of difference. I use a turkey baster and shoot jets of water into the sand. If you haven't done this in a while or very often, youll want to start with part of your sand bed, wait a day, then do the rest. Follow this process for a week or two then you can do the entire sand bed. This process prevents the release of too much "junk" at one time from your sand bed.