Do you use GAC 24/7?

[trout]

Hi,

What are the pros and cons of using GAC in a reactor 24/7? I fluidise Seachem matrix carbon in a phosban 150 reactor 24/7.

I have recently stopped using GFO (Rowa Phos). There has not been any appreciable increase in phosphates and my SPS corals started to look more colourful.

I am beginning to think whether I should just use GAC for a few days every month as opposed to 24/7! Could this give rise to even better colouration of my sps corals.

Nitrates are undetectable (Salifert) and phosphates are below 0.008 mg/l (Rowa Merck).

Thanks in advance.

 

[Boomer]

That is pretty much a personnel choice. Each tank is different. So, your tank may or may not be fine. SPS, tanks are the worst to play with, as sudden changes can cause them to crash and suffer from RTN.


On your Phosphae of 0.008. That is kinda incorrect. That kit "Express's" Phosphate as PO4-P and not as PO4. PO4-P, is only giving the P and leaving out the O4. The conversion is PO4-P x 3.064. So, your Phosphate is really 0.024 ppm. Still very low.

 

[Spinner]

I always have in the past thru a reactor and like the way my reef's looked. I plan this time to use a large pellet carbon and slow the flow to one time system volume per hour. I built an up flow reactor for this build in the past I used in and out thru top. I change my carbon every thirty days with using pre filters on my tanks.:faint:

 

[trout]

I too replace my carbon once a month. I use 150 ml in my 250 lt tank. I use the formula Boomer gave in a carbon related thread in RC (i.e. 1/2 cup of carbon per 50 (US) gallon water- rinse first and then rinse again after one week and use for one month).

@Boomer- should I target to maintain PO4 at 0.024 mg/l or should I take steps to raise it to 0.046 mg/l or even 0.092 mg/l? I feed my fish three times a day (2 X flakes and 1 X frozen) and dose Salifert amino acids once a week in order not to starve my corals. There is no sign of hair algae on rocks. I only get green film algae on glass once every two days, which I suppose may be masking the true PO4 amount in the water column. I keep no sand bed in my tank. Apart from feeding fish even more I cannot think of any other way of raising phosphates other than either stopping the carbon use (or using less and/or less frequently). Interestingly, I never measure nitrates using my Salifert test kit (I assume it is between 0 and 0.1 ppm as I get hardly any pink colour in the test vial). Could this be largely due to four large clams, which are known to be nitrogen sinks in a reef tank?

Thanks in advance.

 

[Boomer]

No, there is no need to raise PO4. Many want your levels. Old saying, have said it many times, " If ain't broke don't fix it". An issue with many, many in this hobby, is "chasing levels", bad, bad idea. I'm sure the clams are helping but have no clue how much.