Diddle822;n676999 said:
So think Chaeto is a better bet then? Im testing like 2.48 with the Hannah checker ...
I wouldn't necessarily say better. Both options have drawbacks. For GFO, it has a lower initial investment, but an ongoing cost of buying GFO, or bleaching what you have to reuse, however even with that method, you will still need to buy GFO from time to time as it will break down gradually. Chaeto has a higher initial investment in lights, more so for a good light, but no ongoing cost. Chaeto can be bought for cheap from an LFS or acquired from another reefer for free. My presumption, and I'm not an expert, is that the Chaeto is less responsive to sudden spikes in phosphates as it takes time to consume the phosphates in the water column. Combined, both will work but one will gradually become redundant. Either the GFO will take all the phosphates and leave none for the Chaeto, or the Chaeto will do the same leaving none for the GFO, I presume the former. If phosphates are as high as that test would seem to indicate I would definitely go with the GFO as that will have an almost immediate effect. For me, I bought Chaeto with the first fish I got for this tank, and I have been growing it gradually ever since. I didn't always have a test kit for phosphates, but by the time I got one, none were showing up. I've only ever lost inverts in my tank, and never had a fish death so the haven't been any phosphate spiking events so I'm not sure exactly how responsive Chaeto is, but I think it is safe to assume that it is not as responsive as GFO, perhaps someone more knowledgeable than myself has some input on that.
As far as the phosphates are concerned, I would think that in 6 months time the initial fauna from the wet rock would have had time to die and decay. That would be the obvious source of phosphates, and with regular water changes, ideally more than once per week if the test turns out to be true, that should diminish.
My preference is to go as organic as possible. I know the Chaeto is always doing it's thing, and I don't have to worry about it becoming saturated between tests and spiking, like GFO can. I will say the carbon gfo kit from brs can be easily cannibalized for parts, and the two stage can be quickly converted to a one if you go Chaeto + carbon, which is what I do with mine. This morning I used the ball valve and rigid piping that came with my two stage for the drain on my skimmer. I have an automatic neck cleaner and it is a pain to remove that sucker to empty the cup, and I had a pretty dramatic overflow of my skimmer drain bucket which sucked.
My very amateur advice would be to get both the two stage carbon + GFO filter, and the a small light for growing chaeto, and transition completely to one or the other in some more time. My tank is about 9 months old, with livestock in it for 6 months on Friday, so I still have a lot to learn, but that is what I have learned from a past build (GFO), and this build (chaeto). Definitely follow jda123's advice as he appears to more about this than I do.