Problems with coral

creefyken · 2026-09-04T19:44:46-0400

I have a innovative marine 20G aquarium started mid February. I used a mix of carib sea and reef saver rock, ocean direct sand, starter bacteria and AF fiji mud. I have put in 3-4 bottles of copepods. I have mostly LPS, and soft corals except for 2 montipora digitatas and a rainbow Stylophora.i have been using reef crystals the whole time no problems. Parameters all good however recently the alk went from 8-10 to 12. The only other big change was i increased my maxspect jump L260 up to 70% and increased the blue and dropped white, red, green to 25% looked great, until all the corals turned brown/maroon and are receeding. Phosphate and Nitrate are undetected. PH 8.3, Calcium 400-440. I have been feeding reef roids, oyster feast, coral inertia NRG 2 times a week and phytoplankton 2x a day. I have added when “needed” tropic marin all for reef and np+. Since the tank is melting down. I reduce the lights to forty percent and went with a even blue red, green, white spectrum.

Saltyreef · 2026-09-04T19:54:26-0400

does your tank have an algae issue? Was your tank started from dry rock? What is your magnesium at? What are you using to measure salinity and are you sure your RODI is at 0tds?

kevgib67 · 2026-09-04T20:05:57-0400

No nitrates and phosphates is not good. I’d rather have to much than to little. You need to get those up.

Saltyreef · 2026-09-04T20:08:28-0400

kevgib67 said:
No nitrates and phosphates is not good. I’d rather have to much than to little. You need to get those up.

There looks to be an algae issue and that may be consuming it and showing a false number.

creefyken · 2026-09-04T20:12:49-0400

Saltyreef said:
does your tank have an algae issue? Was your tank started from dry rock? What is your magnesium at? What are you using to measure salinity and are you sure your RODI is at 0tds?

Using RODI, haven't tested tds but it's pretty new probably had it 2 months. 4 stage. Started with Dry rock. Don't have mag test. 25 % bi-weekly water change , 50% last week. I have had a lot of algae currently mostly green hair.

creefyken · 2026-09-04T20:27:55-0400

Saltyreef said:
There looks to be an algae issue and that may be consuming it and showing a false number.

I can try increasing my NP+. I was afraid I might be over feeding. I would like to have a trace of phosphate and Nitrate but if the algae is consuming it would it still hurt the corals?