Diatoms and carbon dosing

Avp · Mar 17, 2016

I've been battling diatoms in my tank for several months now. Tank has been running for over ten years. Every day the diatoms cover my sandbed and get all over the rockwork. At night they recede and come back when the lights come on the next day. My nitrates are 7 and phosphates are 0.02. I've tried wet skimming along with gfo and granular carbon use for months now, but it hasn't helped. I've also tried large water changes but the diatoms come back. After back and forth conversations with Spectrapure, we determined my RODI water is fine. Would carbon dosing be a good idea to try?

CodyRVA · Mar 17, 2016

Are you 100% positive they're diatoms? Testing for Nitrate and Phosphate can be misleading when you're going through an outbreak.

Avp · Mar 17, 2016

Pretty sure they are diatoms. It's brown and recedes dramatically at night. Not sure what else it could be.

Randy Holmes-Farley · Mar 17, 2016

How old is the tank?

Yes, carbon dosing may be a fine way to reduce nutrients that the diatoms are getting, as might other treatments, such as GFO. GFO also has the advantage that it will directly bind silicate, which diatoms require.

Avp · Mar 17, 2016

CodyRVA said:
Are you 100% positive they're diatoms? Testing for Nitrate and Phosphate can be misleading when you're going through an outbreak.

Randy Holmes-Farley said:
How old is the tank?

Yes, carbon dosing may be a fine way to reduce nutrients that the diatoms are getting, as might other treatments, such as GFO. GFO also has the advantage that it will directly bind silicate, which diatoms require.

Tank is about 10 years old. I've been using gfo but it doesn't seem to be helping.

Avp · Mar 18, 2016

Randy Holmes-Farley said:
How old is the tank?

Yes, carbon dosing may be a fine way to reduce nutrients that the diatoms are getting, as might other treatments, such as GFO. GFO also has the advantage that it will directly bind silicate, which diatoms require.

Thanks Randy. If I start dosing vodka, should I still run carbon and GFO in my reactor?

AllSignsPointToFish · Mar 18, 2016

Yes, you can do all three simultaneously. I've found that a mixture of ethanol and acetic acid works quite well. What kind of skimmer do you have?

Avp · Mar 18, 2016

AllSignsPointToFIsh said:
Yes, you can do all three simultaneously. I've found that a mixture of ethanol and acetic acid works quite well. What kind of skimmer do you have?

Thanks. I have a Jebao D500 skimmer.

Avp · Mar 18, 2016

Are there any downsides to carbon dosing, if done properly? Any chance it makes the diatom problem worse?

AllSignsPointToFish · Mar 18, 2016

Carbon dosing will likely help the diatom issue, not make it worse. Downsides to carbon dosing include reduced pH if you don't have a good skimmer, and white bacterial flocks once the bacterial bloom really gets going. Missing a carbon dosage will also result in a nitrate spike, but other than that, the downsides are not that bad.

Essex reef · Mar 18, 2016

I use no pox by Red Sea dose regular but am having cloud a t moment cleared my diatoms up .just need to reduce amount by 30% once the cloud has gone and gradually increase was told that by tech at redsea

AllSignsPointToFish · Mar 18, 2016

Essex reef said:
I use no pox by Red Sea dose regular but am having cloud a t moment cleared my diatoms up .just need to reduce amount by 30% once the cloud has gone and gradually increase was told that by tech at redsea

That's what I use as well.

Avp · Mar 18, 2016

Thanks for the input. I think I'm going to try the red sea no pox and see how things go. Any other advice using it?

Essex reef · Mar 18, 2016

Avp said:
Thanks for the input. I think I'm going to try the red sea no pox and see how things go. Any other advice using it?

Don't over dose

Avp · Mar 18, 2016

Better to dose too little and be patient?

Essex reef · Mar 18, 2016

Essex reef said:
Don't over dose

Go on web and put in redsea no pox chart it will give you precise dosing directions depending if you using a reactor of some sort

Avp · Mar 18, 2016

I'll do that. Thanks!

Randy Holmes-Farley · Mar 18, 2016

Avp said:
Thanks Randy. If I start dosing vodka, should I still run carbon and GFO in my reactor?

I do, except I use vinegar.

Randy Holmes-Farley · Mar 18, 2016

Avp said:
Better to dose too little and be patient?

Depends on the tank. I've used a very wide range of doses in my tank, in part because I use other methods too (such as macroalgae). In my tank, the exact does is not that important because when one method lags, the others pick up the slack.