is there a need for GAC with an ats?

[dryworm]

does an ats replace the need for gac? any pro and cons to using gac with an ats?

[SantaMonica]

The FAQ has a lot about this.

[Garf]

does an ats replace the need for gac? any pro and cons to using gac with an ats?

Have been running without GAC for 6 or 7 weeks and noticed a slight yellowing of the water over the last couple of weeks. This is not algae residue because my screen is cleaned in the sink as advised. I actually thought my cheapo halides were on the way out but put a bit of GAC in last night and after 18hrs the yellowing has vanished. Was only slight yellowing but now there's no yellow, the water looks loads better.

Gonna go back to my old routine of intermittent GAC now.

[SantaMonica]

Yellow is from dying bottom layers of algae.

[Garf]

Yellow is from dying bottom layers of algae.

I don't think this is scrubber related at all in my case as this used to happen before scrubbing when I didn't bother changing my GAC for long periods. The scrubber is extremely healthy at present. I am convinced it's due to having quite a large soft coral loading and related to the chemicals they use in defence, along with the red colouring that is used in my primary flake food (ocean nutrition - prime reef flakes), I know that this food puts red into the water because when using purigen, it turns bright red.

[RkyRickstr]

I use both gac and gfo once a month or so.

[SantaMonica]

I have not used either one in years.

[Byron]

Hey SM, any chance of an update on your tank as it stands today?

[SantaMonica]

Yes I'll have to start working on that.

[RkyRickstr]

Sm.. what are your po4 readings?

[SantaMonica]

SW zero, FW 0.1

[Wopadobop]

I do run gac for this very reason as I am not sure if scrubbers take up coral chemical toxins. Just to be on the safe side. Stuff is so cheap anyway. I have noticed it does last longer and the carbon source cant hurt the ats either.

[SantaMonica]

No, algae probably does not take up much coral "toxins". However, these coral "toxins" are DOC food too, and will be eaten by bacteria (and corals too) in a few hours.

[Garf]

Has anyone noticed if there is a correlation between running skimmers and GAC, and cyano and dino's. Ie has anyone noticed the cyano, DINO problems getting better when they remove skimmers and GAC from the system (or the opposite).

[kerry]

I have had less of both since running w/o them. I still get them with the scrubber but not near as bad.

[Doompie]

Sometimes when i'm lazy on the cleanings the water colors up green/brownish..but my main "issue" was the build-up of particles in the water column.. which builded up that much that they were very visible on the surface..the skimlayer on the surface of the displaytank (which I never had before..) So the particle build-up became quite heavy over time..at a certain point, when i'd put down my arm in the tank, it was "covered" with these particles..So not too nice..life stock didn't seem too matter though..

No water replacements done ever, havn't had anything in the system except the ATS for almost 10 months.. So I figured: just added a tiny bag of GAC (10 Tspoons) can't hurt..
The coloration vanished within a week..also the particles cleared down.. after one week replaced the GAC, kept it for another week...and all "issues" where gone..
Removed the bag after that two weeks.. now waiting for the next "mandatory" moment ;)