An algae battle I feel like I am losing.

shollis2814 · Sep 23, 2016

36 gallon tank, coming up on 3 years up in January.
First, the pictures of what I am dealing with:

Parameters:
salinity 1.026 (evaporation, I am about to top off)
ph 8.0
kH 8.0
calcium 400
nitrates 10 ppm
magnesium 1100
I did have an iodine/iodide spike. I believe that was what melted some of my zoa colonies.

Lighting
Marine Orbit LEDs
Blues: come on at noon, ramp up for 30 minutes, ramp down to moonlights at 8 pm.
Whites: come on at 12:30, ramp up for 30 minutes, begin to sunset at 7:30, off at 8 pm.

Ecoxotic Stunner strips (2 24")
Come on via lamp timer at 2 pm, click off at 5 pm.

What I have tried:

manual removal

I did a 3-day blackout, which helped tremendously. Followed by a water change and cutting the stunner strips photoperiod back.
Dosing H2O2 before and after the blackout. (1 ml/10 gallons)
Dipping Zoas in 4:1 tank water: peroxide
Running Purigen and Charcoal in my sump

I realize that my nitrates are probably higher and this algae is locking up nutrients. I just did the blackout last Wednesday night-Saturday, and it's already back. I am not overfeeding my fish (if anything I am underfeeding), but it's starting to grow on my Cyphastrea frag. I don't want to add any more corals until I get this under control.

I think at this point I have gotten into my own head and overthinking and overanalyzing.
Suggestions, cries of outrage, 'buck up little camper', all welcome.

salttanklife · Sep 23, 2016

How much of a water change? I'd suggest doing a few large water changes. Are you using Rodi to make your water? Have you replaced the membranes on the Rodi lately?

shollis2814 · Sep 23, 2016

Sorry. I should have included that information.
I did a 30% water change after the blackout, following by a 10-15% water change the following day.
I get my RODI water from my LFS and I have never had a problem with their water in 20 years of using it.