Will intermittent GFO reactor use cause anaerobic issues?

USMA36 · Jan 27, 2018

I have a brs dual GFO and carbon reactor that I only use when my phosphates go above .07 I usually end up running it for 12 hours a day once or twice a week. Will running it this way cause me any issues? Someone mentioned the possibility of. The water becoming anaerobic and causing problems in the tank. If that’s the case, what’s the best way to run GFO when I don’t need it all the time? I’d rather not have to drain everything once or twice a week only to have to set it all up again in a couple of days.

reeferfoxx · Jan 27, 2018

Good question. I would turn it into a chaeto reactor

USMA36 · Jan 27, 2018

Already have two basketballs worth of chaeto running in my refugium.

reeferfoxx · Jan 27, 2018

USMA36 said:
Already have two basketballs worth of chaeto running in my refugium.

Are your phosphates high?

BigJohnny · Jan 27, 2018

USMA36 said:
I have a brs dual GFO and carbon reactor that I only use when my phosphates go above .07 I usually end up running it for 12 hours a day once or twice a week. Will running it this way cause me any issues? Someone mentioned the possibility of. The water becoming anaerobic and causing problems in the tank. If that’s the case, what’s the best way to run GFO when I don’t need it all the time? I’d rather not have to drain everything once or twice a week only to have to set it all up again in a couple of days.

That makes no sense to me. The only problem I could see would be related to using gfo in general and that's pulling out phosphate too quickly. Imo if you are only needing to run it for 12 hrs you are using way too much. Why don't you just run a very small amount 24/7 to maintain your phosphate at .07 instead?

USMA36 · Jan 27, 2018

Phosphates fluctuate. When they get up to .o7 I turn on the reactor for 12 hours or so. I test the water after that and I’m back down to 0. I don’t like running 0 all of the time. I started seeing some issues with my corals.

BigJohnny · Jan 27, 2018

USMA36 said:
Phosphates fluctuate. When they get up to .o7 I turn on the reactor for 12 hours or so. I test the water after that and I’m back down to 0. I don’t like running 0 all of the time. I started seeing some issues with my corals.

I wasn't suggesting running zero I was suggesting running a smaller amount constantly to keep them between say .04-
07. Better than stripping .07 out of the water in 12 hrs. Having said that, the margin of error for your test kit is probably max .04, just fyi. Have you experienced problems with phosphate above .07? Are you sure it would keep going higher? How high? Just some thoughts.

Wait, are you leaving the gfo in the reactor without flow in between use? If so then yes that could create an anaerobic environment within the reactor but I'm not really sure what problems that would cause if any. Your best bet would be to ask randy on his chemistry forum. Or, just take it out between uses (obviously not ideal).

Cory · Jan 27, 2018

If by anerobic you mean create h2s then yes for sure it will. Best way is to have it turn on and off every 15 minutes.

USMA36 · Jan 28, 2018

BigJohnny said:
I wasn't suggesting running zero I was suggesting running a smaller amount constantly to keep them between say .04-
07. Better than stripping .07 out of the water in 12 hrs. Having said that, the margin of error for your test kit is probably max .04, just fyi. Have you experienced problems with phosphate above .07? Are you sure it would keep going higher? How high? Just some thoughts.

Wait, are you leaving the gfo in the reactor without flow in between use? If so then yes that could create an anaerobic environment within the reactor but I'm not really sure what problems that would cause if any. Your best bet would be to ask randy on his chemistry forum. Or, just take it out between uses (obviously not ideal).

Yes I am leaving the GFO and carbon in the reactors while they are off. I did post this in his chemistry forum. I am hoping @Randy Holmes-Farley chimes in as there seems to be some confusion. Some people think it won’t do any harm others think it will do a lot of harm. As far as running a small amount, won’t a small amount strip all phosphate and just exhaust itself sooner? Is there a way to determine the right amount for a 100 gallon total water volume system? I used the brs calculator but I think that was way too much I was always showing 0 on my Hannah phosphate meter.

USMA36 · Jan 28, 2018

Cory said:
If by anerobic you mean create h2s then yes for sure it will. Best way is to have it turn on and off every 15 minutes.

Will running it for 15 off for 45 cause that issue?

saltyfilmfolks · Jan 28, 2018

@jsker I belive you had an issue with bio pellets.

@USMA36 , good follow up.

Cory · Jan 28, 2018

USMA36 said:
Will running it for 15 off for 45 cause that issue?

No you should be okay with that rate.

saltyfilmfolks · Jan 28, 2018

Honestly I’d just lower the amount of gfo in the the reactor.

USMA36 · Jan 28, 2018

Wouldn’t lowering the amount of GFO in the reactor still strip the water at the same rate as the correct amount? My understanding It will just exhaust quicker.

saltyfilmfolks · Jan 28, 2018

Double post. Sorry.

jsker · Jan 28, 2018

I have not read to were hydrogen sulfide built up in GFO. I did run into an issue when running my old bio pellet reactor to slow.

The suggestion of less is best from the above, works in your case with the GFO. I run 3/4 to a cup in my reactor that holds 6 cups of GFO. and I run the GFO 24/7 unless it is feeding time. The reactor shuts down during feeding and fires right back up 5 minutes after feeding.

USMA36 said:
Wouldn’t lowering the amount of GFO in the reactor still strip the water at the same rate as the correct amount? My understanding It will just exhaust quicker.

Not necessarily, what is being run now is to much and is stripping the water. Running less will keep the phosphates steady instead of the climb and reductions.

Here is an article by Randy about GFO link

jsker · Jan 28, 2018

saltyfilmfolks said:
Double post. Sorry.

That's it, off with your hands

saltyfilmfolks · Jan 28, 2018

USMA36 said:
Wouldn’t lowering the amount of GFO in the reactor still strip the water at the same rate as the correct amount? My understanding It will just exhaust quicker.

If a half cup running 12hr removes .05
A quarter cup running 24 should remove .05 no?
(Made up numbers)
And exhaustion will depend on what other stuff it’s pulling. Beside Po4

DSC reef · Jan 28, 2018

This is interesting. I had gfo sit in the reactor for a few days and it turned to hydrogen sulfide. I wonder if organics in the saltwater had something to do with it. That freaked me out and took the reactor off line. I run gfo in a bag in the sump. I would think running a less amount would be safer than letting it sit stagnent.

saltyfilmfolks · Jan 28, 2018

DSC reef said:
This is interesting. I had gfo sit in the reactor for a few days and it turned to hydrogen sulfide. I wonder if organics in the saltwater had something to do with it. That freaked me out and took the reactor off line. I run gfo in a bag in the sump. I would think running a less amount would be safer than letting it sit stagnent.

IMO , you are correct. It’ll be the organics in the water and bacterial population in the water.