Diatoms won't stop

[Drkphant0m2]

My tank is about 2 years old and I have constantly struggled with diatoms. It only grows on the glass and sand, never on the live rock. After cleaning the glass, it only takes about 2 days for it to start growing back. I have also never been able to grow coralline algae. I have switched to ro/di water and switched salt mix from reef crystals to instant ocean and nothing has worked. I never overfeed by the way. Maybe it's not diatoms, I'm not sure. But it is brown and very irritating. Can someone please help.

 

[jnelson]

Is it brown and "dusty" or is it more of a slimy consistency with bubbles? If it's the latter it might actually be dinoflagellates, but those usually grow on rock as well. If it's the former, then it's definitely just diatoms - might want to get a bigger clean up crew (snails and/or hermits) to snack on it.

 

[Drkphant0m2]

Sorry for it being sideways but here is how it looks in larger problem areas. It definely looks like dinoflagellates now that you mention it.

 

[LongIslandAndy]

It looks like diatoms they usual starve without silica. How long have you been using the RO water?

 

[Drkphant0m2]

I've been using ro water since December

 

[LongIslandAndy]

Okay, you can get some nassarius snails to move the sand around and also a fighting conch. Check you PH and alk and if it is low bring it up a little bit.

 

[JavyJaverson]

What methods of nutrient export are you using?

 

[Drkphant0m2]

I will check the alkalinity and pH when I get home. Also for nutrient export, I do 10% water changes every 2 weeks and use a carbon/GFO Reactor. There's also the protein skimmer and chaeto algae

 

[jvu61]

you may want to make sure your rodi is at zero tds. I would als test for silica as well as po. if any of those are to high it may mean your not using enough gfo or you skimmer may be to small for the tank may also not be enough water flow. IMHO always test first before making changes

 

[Dejathoris]

Looks like dino to me. Since your pic is sideways it's hard to tell but if you look closely you can see the slimy strands sticking out of the sand. They say having a blackout for a couple of days usually helps. I'm not as experienced as others so maybe someone can give you a better
solution.

 

[Drkphant0m2]

I checked my parameters and my pH was 8.1, Mg was 1400ppm, my Ca was 450ppm and my dKH was 5.8. I had no idea alkalinity was so low (must have been from switching salts. Also the ro water's Tds meter reads 0.

 

[LongIslandAndy]

Try to get that DKH up between 8-12. I would dose a 2 part product and just dose more alk then calcium. If you just use a buffer and not a balanced product you alk/dkh will be like a yo-yo. How large is the tank

 

[Drkphant0m2]

I just realized my timer for alkalinity has been broken, no wonder it's so low. But normally I dose 2 part and my tank is 75gal