Phosphates, GFO, NOxPOx

TangingOut

New member
Is it possible to maintain low phosphates ( currently around 0.08 ) without GFO and without starving my fishes? I currently feed 2-3 times daily but not heavily. I've been running GFO in a reactor and have been dosing NOxPOx, but would like to take the reactor offline.

NOxPOx has worked great for me controlling nitrates, but the only times I saw a reduction in phosphates was after I changed out the old GFO. Is there anyone out there who use NOxPOx to maintain low phosphate levels without GFO and who feeds their fish well?
 

eddiereefs

New member
The problem that you are encountering is that carbon dosing what nopox is, is great for reducing nitrates however studies show that while it can reduce phosphate it is mainly used to bring nitrate levels down. I run gfo and carbon dose at the same time for that exact reason, the beauty with carbon dosing is that u can over feed ur fish as levels n the tank are low.
 

TangingOut

New member
I entend to continue carbon dosing because it's really simple once you figure out the correct dosage. However, my main concern is with phosphates. Will it increase if I take my GFO reactor offline while still dosing NOxPOx?
 

eddiereefs

New member
It probably will but eventually they should go back down. Carbon dosing is just more effective at removing nitrates but it will lower ur phosphates over time. If it doesnt just simply run more gfo
 

droog

New member
I'm in the same boat as OP. Carbon dosing (also using NOPOX) keeps my nitrates about 7ppm and PO4 about 0.1. Adding GFO to the mix gets Po4 to about 0.04 or so (according to my Hanna ULR phosphorous checker anyway).

I too like the convenience of carbon dosing via automated pump, and I hate using reactors. Just seems to messy and tedious.

I'm now using BRS single reactors and BRS HC GFO. The reactors look similar to RO/DI filter cannisters and the media goes into a cartridge similar looking to a sediment pre-filter. Much easier to use than other reactors. The flow is dialed-in and I have a couple of spare cartridges so my process is:

- weigh the GFO into a empty cartridge on my electronic kitchen scale
- rinse cartridge under my sink (RO) faucet for minute or so
- stop pump
- swap cartridge
- restart pump
- clean out old cartridge

Only needs doing once every 1-2 months. I need to scrape algae of my front panel after about 5 days. When that period drops to 4 or 3 days need to replace GFO.

Carbon dosing only for about 10 months. I had problem algae growth. GFO in a bag didn't seem to make any difference. GFO in a reactor was a pain to setup, but has the advantage of actually working.
 

droog

New member
I read that using Kalk in ATO might help "precipitate" PO4 out of solution (possibly as calcium phosphate). It seems its somewhat accepted by hobbyists though the mechanism is not well understood or proven. So NOPOX + kalk ATO might help a little. I do ATO with Kalk but it didn't control PO4 enough on my system, and I don't think I'm overfeeding.
 

TangingOut

New member
Thanks Droog. The reason I want to take the reactor offline is because I can no longer get it to fluidize in my spectrapure dual reactor, even with the flow completely off on the carbon side. I've tried everything from checking lines for blockage, testing pump, cleaning cartridge screens, removing cartridge filter, and modding the screens to get more flow. Oh, I've also tried less GFO.

I was hoping I can maintain phosphates with just NoPox as I would most likely sell on the reactor. I may just do that anyways or try a new cartridge before taking that route. I think I should've bought a purpose built reactor to begin with instead of a modified RO filter.
 

droog

New member
Looks like a good reactor, similar to the BRS ones. Needs the appropriate pump MJ1200?). Assuming you have that, try removing sponges if there are any (the top one is not needed for GFO, you may be able to lose the bottom one also)

Also are you running socks or other mechanical filtration? Make sure the pump supplying your reactor is downstream of the filter, otherwise debris can build up over time reducing flow.

Finally what media are you using? The BRS HC GFO seems to fluidize easier than others media have tried (Rowa Phos and phosban). Maybe worth a try

-droog
 

TangingOut

New member
Trust me, I've tried everything. The pump (mj1200) is pumping the same amount as ever and is downstream in the sump with a pre-filter. All sponges have been removed and I'm still using the same media as always.

It's really frustrating since it was working fine before.
 

Scrivo

New member
This seems a good thread to discuss this, can anyone advise on my Nitrate issue.....? Currently sat at 160ppm....

I have a 90 gallon cube tank with about 8 fish and a good amount of LR. I only really feed them once a day.

I plan on doing a 50% water change this weekend but I am concerned that it might just be a short-term fix and not a solution. I need to get to the bottom of the problem....

My return pipe takes water to the first chamber of my sump containing bio-balls, then the water moves to a section full of porous rock (Alphagrogg I believe its called), then through some sponge media before hitting the Deltec (a very recent addition within the last week) and into the return pump to finally push it through a UV....

I can already anticipate where I am going wrong but wondered what you 'experts' might advise and the course to take to get there as I am not going to just take it all out at once in order to avoid a major biological disruption....

I have space in the sump but wondered what suggestions could be sent my way.

I don't really have an Algae problem but I just feel the tank isn't up to the standard I am looking for

Would some Carbon in a bag help if I replaced the bio-balls with that as its a high flow area?

Advice please...
 
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