High Nitrates & Phosphates

fishnugget1 · Aug 12, 2023

I have been suffering with Red Nuisance algae (Cyno ) & Brown Algae on the sand for months. Restarted tank last December. Red Sea Reefer 750. @ 16 fish. I have used chemiclean, red goes away & comes back. Water changes using ro/di water. No help. Nitrates at 19.5, Phos .08. Salinity .25, Mag 1335, Calc 425, Alk 8.45. Stable.
I used floss in filter cups for mechanical filtration & large skimmer. Temp 77.3-78.5. ESV 2 Part on dosers. Some growth but tank ugly on sand only. 3 Eco Tech Pros with 4 ATI t-5 bulbs.
2 Blue, 2 Coral. Using co2 scubber. Have refugium that tends not to grow much ans always has red cyno in it.

Main issue is to rid most algae on sand. Is my Nitrates & phos too high? Can that cause this issue? I am constantly fighting this. Do water changes every 3 weeks of 20%.

Any ideas what I should do or use.?

Spare time · Aug 12, 2023

I'd try using chaetogro for the refugium and assure the light is good (right color, intensity, etc). Phosphate is a little high but not terrible. What test kits do you use?

fishnugget1 · Aug 12, 2023

Hanna & Salifert

I am using chaeto

Lavey29 · Aug 12, 2023

Phosphate and nitrate are fine. Since you restarted the tank 8 months ago you are still in the ugly phases. Dropping harsh chemicals in the tank kills off your biome and opens the door for problems. Cyano is typically caused by to much light and lack of flow on the sandbed. Weekly water changes. Add pods and phytoplankton. Dose PNS probio which is a natural heterotrophic bacteria that eliminates organic waste feeding algae. Focus on maintaining good numbers and stability.

MrGisonni · Aug 12, 2023

Nitrates and phosphates are fine. Get that chaeto growing. Increasing flow is a good idea. Reevaluate light spectrum, intensity and photoperiod on both the display and refugium.

Koty · Aug 12, 2023

IMHE, I would never use antibiotics/chemicals as they are temporary, wrong solutions, and essentially a setback. As others have said, your parameters are fine. Get a real sand-sifting Gobby, and your cyano issues on the sand are history. Your tank is still maturing; give it time to evolve.

Miami Reef · Aug 12, 2023

What are the brown algae you are mentioning that’s also on the sand?

Here’s my advice for cyano:

Increase flow.

Stir the sand-bed about once a week to release organic debris that may be fueling the cyano growth. Do not do this with deep sand beds.

Run activated carbon to adsorb organics.

If possible, I would dose sodium silicate to encourage diatoms to outcompete the cyano.

If that still doesn’t seem to help, I’d try dosing hydrogen peroxide or bacterial additives.

ninjamyst · Aug 12, 2023

Koty said:
As others have said, your parameters are fine. Get a real sand-sifting Gobby, and your cyano issues on the sand are history.

DO NOT get a sand sifting goby. It will bury corals on the sandbed...create uneven sand mounds, spike nitrate / phosphate by constantly turning over sand.

Koty · Aug 13, 2023

ninjamyst said:
DO NOT get a sand sifting goby. It will bury corals on the sandbed...create uneven sand mounds, spike nitrate / phosphate by constantly turning over sand.

Create uneven sand mounds? Seriously? What is wrong with that? Looks too natural? I don't care for some sand sprayed occasionally on my corrals. They are used to cope with it. I have a SSG for almost two years now, and he is my best worker. He moves sand from place to place, and it's fun. He piles pieces of mussels that I drop. By the way, my phosphates and nitrates are stable. For full disclosure, I also have 4 wrasses that sleep in the sand every night and dive in occasionally during the day. Thus my sand looks white and clean all the time. Here is my tank (I placed two Trachiphilias in the sand):