Will GFO speed up the carbon dosing process?

[Murraydar]

I started carbon dosing about six weeks ago. My phosphates are high (.83) and I'm increasing my dose week by week until it starts coming down.

My understanding is that po4 can be bound in rocks and sand and it can take quite a while to bring it down. However, some of my corals are looking a bit sad and I believe its due to the high po4.

I suppose my question is this: Will the addition of some GFO help remove the bound po4 faster? Or perhaps lighten the load that the carbon dosing needs to remove? Thanks!

 

[Lasse]

Whats your NO3 level and which tests do you use?

Sincerely Lasse

 

[Murraydar]

No3 is about 15ppm. It hasn't really changed much since I started carbon dosing either.

I use nyos for No3 test and a 713 Hannah checker for p04.

 

[Lasse]

The GFO will speed up the removing of PO4 but it will only take away PO4 - not NO3. In the best of worlds - DOC (Disolved Organic Carbon) dosing will remove both some PO4 and NO3. Release of PO4 is normal a slow process (if the environment around the stones is aerobic and/or pH > 7.9 ) but it will be speded up in some way if the PO4 content in the water is low. How long time have you dosed DOC? what type and how much/day

Sincerely Lasse

 

[Murraydar]

I've been dosing for about two months I'd say. I'm using a diy nopox mixture ( vinegar, vodka, water) and I'm currently up to 10ml a day. Increasing it by about 1ml per week.

From what I've read it can take a while to remove po4 from a system, as in months. I'm just kinda surprised that I've seen basically zero change in either No3 or po4 whatsoever. I have great water movement and a well operating skimmer as well, should be removing the bacteria just fine.

 

[Lasse]

Size of aquarium ?

Sincerely Lasse

 

[Murraydar]

Woops forgot that. Minus rocks and sand I'd say around 75 gallons.

 

[Larry L]

Have you seen your nitrates start dropping since you're begun carbon dosing? If not, then maybe just wait a while and/or gradually increase your dosing to build up the bacteria populations to a level where you see noticeable results. If you have seen your nitrates dropping, then you most likely should have also seen some drop in phosphate - unless like you said there's a lot bound up in your rock or substrate, in which case it will keep releasing any time the phosphate level in your water gets low.

If you want to bring your phosphates down initially to get them to a level that's maintainable by your carbon dosing, you might want to consider one of the liquid lanthanum chloride phosphate removers rather than GFO or the other granular phosphate removers. I find the liquid ones easier to manage and much more predictable as far as how much and how fast you can drop the levels, and there's no guessing about how much granular media to start with or how long it will last before it's depleted. I wrote a calculator to help me with dosing the liquid stuff because it's easy to get confused with the math and overdose:

http://larryl.emailplus.org/fish/dosing-instructions-phosphate-removers.html

I usually go slow and use half the recommended dose, just to be safe. Don't be surprised at first if after dosing the levels are not as low as you would have expected, because of the issue of phosphates leaching from your rock or substrate, but eventually you should be able to get things to stay at a consistently lower level.

 

[Murraydar]

Thanks, I was actually just starting to read up on that stuff. I'll give it a look.

 

[mike321]

Was using nopox for about a month and a half with no change. No3 was 50ppm and p04 was at 0.86.
Once I added gfo to a reactor the no3 dropped to 5ppm and p04 was at 0.14.
Seemed like the gfo sped up the process for me.