[druxboyz]

quite a predicament you got going there! its going to be tough getting that laterite in decently with lots of water, so i think that the best way is to do what you wrote. Remove the fish with your old water and re-add that. I think the fish should be fine as long as youre careful. (im no expert). That route would probably be better than doing it with the fish in the tank anyway, so you dont have much choice. As for the rena, the sand should settle to the bottom pretty quick because it is dense. So i dont think any should be getting sucked into the impeller unless your inlet is relatively close to the sand itself. I would leave the filter on after the sand is settled with the water red, but also making sure the inlet is high off the ground. That's all i got, hope others can give you more thoughts and suggestions!