Algae outbreak - need help

Freemason1970 · Dec 28, 2020

I cannot seem to get this algae issue under control. Any advice would be greatly appreciated. The tank has been running for about a year now. I do water 20 gallon water changes every 2 weeks. Below is the tank information.

125 gallon
30 gallon sump
2 filter socks
GFO in reactor
Skimmer
Auto top off
11 small fish
6 different frags
3 Radion lights at 45%

Parameters
Alk - 9
Ammonia - 0
Calcium- 500
Mag - 1400
Nitrate - 2
Nitrite 0.05
Ph - 8.1 to 8.3
Phosphate- .03
Salinity - 1.026
Silica - 0.03

Greg P · Dec 28, 2020

I see both red and green cyano. It's a bacteria, not an algae
Search how to deal with cyanobacteria

brandon429 · Dec 28, 2020

Due to localization shown in pics my number one fix for that system would be 100% siphon cleaning by hose remove all the topical growths, the equivalent of 30 or so gallons big water change.
then in the clean condition install a common small in line pond sterilizer UV off Amazon, about $150 dollars. Then based on pics above what isn’t zapped will be nice clean rocks those are excellent devices for large systems. This isn’t a parameter or bad water issue, per pic details. Reefs are meant to grow those organisms. If we want an unnatural outcome to a balanced system, uv is the ticket.

laup18 · Dec 28, 2020

Your Nitrite should be 0 and Nitrate is kind of low for me. Microbacter7 could be an initial step. More good bacteria will help to fight the cyanobacteria for sure.

Nigel35 · Dec 28, 2020

I agree with brandon429. manually get rid of as much as you can and then look into UV sterilizer and also a CUC if you don't currently have one. Most of your algae problems look to be on the sand bed. Look into a sand sifting star, tiger conch etc. or even a diamond goby.

Greg P · Dec 28, 2020

laup18 said:
Your Nitrite should be 0 and Nitrate is kind of low for me

True, but it could also be a test kit issue for the NO2
I don't see any SPS in the photos so unless there's a diatom issue I wouldn't worry about raising N&P

Freemason1970 · Dec 28, 2020

Thank you all for your quick response. I realize I have a small raise in nitrite, but how much higher should the nitrates be?
During the water changes I have been using a hose to try and get as much as I can during water changes but it keeps coming back about a week and a half later.
I've been thinking of getting a UV system. Maybe that would help.

Freemason1970 · Dec 28, 2020

Nigel35 said:
I agree with brandon429. manually get rid of as much as you can and then look into UV sterilizer and also a CUC if you don't currently have one. Most of your algae problems look to be on the sand bed. Look into a sand sifting star, tiger conch etc. or even a diamond goby.

What is a CUC?

Greg P · Dec 28, 2020

Freemason1970 said:
... but how much higher should the nitrates be? ...

Freemason1970 said:
What is a CUC?

Don't be too concerned about raising your Nitrates (NO3) at this point.
As I wrote above, I don't see any SPS in your photos, nor any Diatoms at this time.

Clean Up Crew

Greg P · Dec 28, 2020

I'd suggest at this point you don't tinker with your parameters unless they will directly help you combat the Cyanobacteria. And personally for what life I see in the photos, your current params are fine.

Later on, IF you decide to get some LPS/SPS, consider lowering your Alk to 7.5/8.0 with your current Nitrate (NO3 or N) and Phosphate (PO4 or P) levels.
Or keep your 9 dKH Alk and raise N&P to (roughly) 2-5 or even 10 & 0.03-0.06

For now, deal with just one issue at a time !!

Freemason1970 · Dec 28, 2020

Greg P said:
Don't be too concerned about raising your Nitrates (NO3) at this point.
As I wrote above, I don't see any SPS in your photos, nor any Diatoms at this time.

Clean Up Crew

I do have some snails, hermit crabs and a cucumber. There is a lot of brown on the rocks and I keep scraping it off the back of the tank.

Greg P · Dec 28, 2020

Freemason1970 said:
I do have some snails, hermit crabs and a cucumber. There is a lot of brown on the rocks and I keep scraping it off the back of the tank.

That brown could be algae, or diatoms.
Your tank is still maturing and I see it looks like you used some base/dry rock to start with?
For now, just go after the Cyano, and scrape/brush the brown stuff right before a WC or sock change