Okay guys, I have an algae issue and I am hoping that I can get some ideas on how to approach this. I know the mantra on algae control, but this tank is not a typical tank and so I am blazing new ground here. I have a buddy with a very similar setup going through the same issues. I think we missed something in our setup but not sure what it is.
Okay , so here is the tank. Standard 90 gallon tank, 48x18x24. Lighting is 2x250w MH 10k bulbs, 4x54w T5 supplemental (3 ATI Blue+; 1 UVL 75.25). The system is setup as a lagoon/seagrass environment. I have 50 pounds of LR in the tank, and a 5” sand bed. I cannot really add more LR as I need to preserve the open sand if at all possible.
Current inhabitants of the tank are a lawnmower blenny and a yellow watchman. Inverts are two cleaner shrimp, a tiger pistol shrimp, a montipora digitata frag, a couple of mushrooms and some anthelia. There is a BSJ that went awol about 10 days ago.
When the watchman is out in the evening, the tank will get fed once a day. If he is in his burrow and has collapsed the entrances, I do not feed; so the tank gets fed between 4 and 6 times a week. Food is rinsed in RO, and is either frozen mysis or Rods. Couple times a week a few shrimp pellets are tossed into the fuge.
Sump is a 30 long with a fuge. Fuge is about 20” long and is growing gracillaria and chaeto.
Mechanical filtration is filter socks; 200 micron socks that get swapped out every 2-3 days. Water changes are 20 gallons per week. RO/DI, 0 TDS, Brightwell Salt
NO3 – 0 meg/l
PO4 - not detectable
Mg – 1280
Ca – 410 ppm
SG – 1.025
Temperature – 76-78
CUC – snails. Ceriths, dwarf ceriths, nerites, one turbo, two cowries. No hermits or emeralds. They would cause a lot of damage to the infauna of the sandbed and so cannot add them. A constraint of the lagoon.
Skimmer is a Reef Octo DNWB 150; produces almost nothing
Water movement is an MP20, K4, and the return. Tank is about 5 months old.
I have uncontrolled hair algae growth all over my rocks
What I am doing to try and get things under control
Upgrade skimmer to SWC 160 Cone
Add 15 pound base rock to fuge
Increase turnover through sump (from 600 GPH to 1000 GPH)
Planted black mangrove in DT (grown about 5” in 3 weeks which is just crazy. Started with 2 leaves, now 10)
Increased fuge photo period to 18 hours a day
Added chaeto ball to DT in one of Jays pod hotels
Added NP biopellets to BRS media reactor (think vodka dosing)
Now, everything seems healthy. The seagrass, the monti was just a nub that broke off at work and is growing like gang busters. There is so little out there on the cycling of a seagrass tank I don’t know if I am doing something wrong or this is just part of the process to reach equilibrium. Any suggestions as to what I could do or do different would be much appreciated
Okay , so here is the tank. Standard 90 gallon tank, 48x18x24. Lighting is 2x250w MH 10k bulbs, 4x54w T5 supplemental (3 ATI Blue+; 1 UVL 75.25). The system is setup as a lagoon/seagrass environment. I have 50 pounds of LR in the tank, and a 5” sand bed. I cannot really add more LR as I need to preserve the open sand if at all possible.
Current inhabitants of the tank are a lawnmower blenny and a yellow watchman. Inverts are two cleaner shrimp, a tiger pistol shrimp, a montipora digitata frag, a couple of mushrooms and some anthelia. There is a BSJ that went awol about 10 days ago.
When the watchman is out in the evening, the tank will get fed once a day. If he is in his burrow and has collapsed the entrances, I do not feed; so the tank gets fed between 4 and 6 times a week. Food is rinsed in RO, and is either frozen mysis or Rods. Couple times a week a few shrimp pellets are tossed into the fuge.
Sump is a 30 long with a fuge. Fuge is about 20” long and is growing gracillaria and chaeto.
Mechanical filtration is filter socks; 200 micron socks that get swapped out every 2-3 days. Water changes are 20 gallons per week. RO/DI, 0 TDS, Brightwell Salt
NO3 – 0 meg/l
PO4 - not detectable
Mg – 1280
Ca – 410 ppm
SG – 1.025
Temperature – 76-78
CUC – snails. Ceriths, dwarf ceriths, nerites, one turbo, two cowries. No hermits or emeralds. They would cause a lot of damage to the infauna of the sandbed and so cannot add them. A constraint of the lagoon.
Skimmer is a Reef Octo DNWB 150; produces almost nothing
Water movement is an MP20, K4, and the return. Tank is about 5 months old.
I have uncontrolled hair algae growth all over my rocks
What I am doing to try and get things under control
Upgrade skimmer to SWC 160 Cone
Add 15 pound base rock to fuge
Increase turnover through sump (from 600 GPH to 1000 GPH)
Planted black mangrove in DT (grown about 5” in 3 weeks which is just crazy. Started with 2 leaves, now 10)
Increased fuge photo period to 18 hours a day
Added chaeto ball to DT in one of Jays pod hotels
Added NP biopellets to BRS media reactor (think vodka dosing)
Now, everything seems healthy. The seagrass, the monti was just a nub that broke off at work and is growing like gang busters. There is so little out there on the cycling of a seagrass tank I don’t know if I am doing something wrong or this is just part of the process to reach equilibrium. Any suggestions as to what I could do or do different would be much appreciated
My apology John. Welcome to RS! We're glad to have you here with us 
