so this weekend i want to change my crushed coral to aragonite... i will also be adding my modded ac70 to the system as soon as it arrives. my question is, when i suck out all my old sand/crushed coral all my pods are gonna go too i assume. how can i make sure that they come back?maybe i'll just siphon out as much water as i can then scoop up about 80-90% of my old stuff so that i know i will be leaving behind extra bacteria and some pods to repopulate the new aragonite? im going to use not live aragonite so that my live rock can seed it.

what do you all think about this?

no suggestions?

I'm not an overly experienced reefer, but from what I have read in other posts, you should siphon out the sand/crushed coral bits at a time so the beneficial bacteria in your live rock has time to compensate for the loss of bacteria from the substrate. I'm not sure about the pods. Personally, I would wait until the fuge is set up for a few weeks so the pods can populate it before removing all of the substrate. Pods live in/on the live rock too though...

But..I'm new at this too, so I may be wrong, hopefully someone with more experience can come and help you out.

I'm usually a pull and replace kinda guy but you have a very small tank .. so I to think i would get the fuge setup and running well .. occupied with pods etc prior to removeing your old substrate.

with the concern over pods etc I would guess that your tank is fairely mature so this will be a large change. Might choose to go slow..

but if you do go all at once.. the pods will return from the rock that is left .. over time...

cool thanks for the input fellas. i'll do that. i want a shallower sandbed so i'll siphon some of it out a lil at a time during water changes and gravel vac a lil bit at a time.