The Puffer Forum

I have gone from FW to BW to SW but I still have FW substrate. Its like the colored gravel you see a lot except its smaller and black and white. so I have 1/2 black and 1/2 white FW gravel in a fowler tank. There are lots of things living in sand that i can see which leads me to believe that i have a pretty good build up of biofilter in it. do i really need to switch to aragonite or can i keep this stuff indefinitely?

How is your PH and Nitrates. Id be concerned about nitrate spikes due to left over food and stuff in the rocks

PH 8.2 Amonia 0, nitrite 0, nitrates 15, KH 450ppm. the tank is about 7 weeks old.

you can use any substrate you want. People use aragonite for its buffering capabilities (pH).

using aragonite means a little safety on your side, but not using it means more tests and closer monitoring.

Yep as long as your PH is stable and your nitrates stay down I wouldnt worry about it

Minor quibble on J-P's comment. Aragonite is for alkalinity support, not just pH. In most tanks the pH is the quickest test for good alkalinity, but pH alone does give you same info as does the alkalinity.

FW substrates should be inert, other than for Rift Lake and other high-hardness tanks.

SW substrates historically and practically are not, but offer altalinity support. Over years, they may require replenishing as they dissolve as needed.

Long-term you may require some alkalinity support, but there are several ways of providing that where an inert substrate is being used. It is not a big deal.

thank you for the clarification

For some reason it had completely slipped my mind.

I feel you are best with aragonite or sand in there.

Off-topic: Welcome back, PP! We missed you!

I cannot argue that aragonite is not the best, as I push it all the time myself. But on an establish and biologically stable tank, I myself would not re-do the substrate from inert to alkalinity-supporting just for that. I have moderately soft and acid water myself, and have been providing other alkalinity support processes to my Rift Lake and BW and SW tanks for decades. To me it is a routine practice and does not bother me at all. To folks who have not done such, it may be new and strange, but it still is not difficult or tricky.

I've got well water, luckily the only thing in it seems to be bicarbonate (a lot 20+dKH) so keeping alkalinity up shouldn't be a problem at least until I can pick up an RO/DI.

Well water is awesome.

I loved it when I was on mine. RO/DI is great if you are going for corals. FOWLR, it is still good for keeping problem algae at bay but I don't know if it is 100% necessary.