GFO and GAC in Canister filter (like Randy's)
 

Randy, you've mentioned that you run GFO and GAC in canister filter. I'd like to do the same since I already have Magnum 350 :)
So, here are some questions:

1) if I drop 150gramm GFO (lets say Phosban) into canister running 350gph, wont it reduce GFO's effectiveness? According to 2LIttleFishes, ~90gph is what's needed.

2) With GAC needed to be changed frequently, do I use the same schedule (lets say 2 weeks) to replace GFO? Or I could use leave it there for longer time?

3) Have you tried and/or recomend to use GFO with ChemiPure? Just because they advertize longer life span vs GAC?

Thanks in advance

shameless bump ;)

The recommended gph is to keep the granules from bouncing around and grinding up in a loose setting. You can run it faster through a cannister filter. Your change schedule should be based on the effluent coming out. If it starts showing phosphate, change it.

Higher flow never hurts the actual binding effectiveness of binders like GFO, but it might grind it to dust if it is moving around too much.

The schedule depends a lot of the level of phosphate concern you have. I use relatively little GFO and change the whole thing only every 2 months or so.

Gotcha, thanks.
One more question: 2 month changing for carbon too? I thought that it is supposed to be changed at least once a month otherwise it becomes bad for the tank.

I presume that the concern with leaving carbon in a long time is that it may develop a coating of bacteria that may facilitate the conversion of ammonia to nitrate. That might be true, but in my tank nitrate is never a concern as I export plenty of nitrogen via growing macroalgae.

But if you want to avoid that issue, changing it faster can work. I generally recommend 1-2 months on carbon used to reduce organics and yellowing of the water, however.

Thanks Randy. Last question, do I just drop GFO in a bag in canister and fill the rest with carbon, or there is a better way?

I mix them together and my media holder in the cannister holds it it, but not all will do that, so a bag is OK. :)

Thanks Randy, mixing away :D

:thumbsup:

Good luck. :)