I've never switched substrates before so forgive my ignorance but can I add sand to the tank while the fish are in the tank? Or do i have to take the fish out and put them back in later? Right now I have nothing on the bottom of my tank because i moved it and took all the gravel out.
Thanks

ive added and removed substrate from the tank while my fish is in the tank just make sure yr canisters r switched off so that u dont get any sand going through yr filter.

i used a big jug filled it with the substrate and slowly lowered it to the bottom and then just tipped it.

this is really a crap job and u need to be very carefull around yr heaters,filters and fish.

do it over a couple of days add a few jugs every day.

Thanks, I will add a little at a time and try to bring it all to te bottom first before pouring it out.