Originally Posted by
nietzsche
i would say to get a large container that can hold the water, place your fish in there with some live rock, heater, and some water movement while you put everything in your larger tank. i wouldnt know the best way of transferring the sand, but i just scooped it up and placed it in the newer tank. you're going to have to monitor ammonia, nitrites, nitrates to make sure you didnt kick up anything that was trapped in the sandbed
make sure you have the water ready in the 75g as well too thats at the same temp where your fish are coming from
I agree with all this, but if your budget allows I would throw out the old sand and put in all, or at least a good portion of, lnew 'live' sand. I have done this with several tank upgrades and never had a problem. If you use the old sand I guarantee you will have a nice nitrogen surge and end up spending more time, and even maybe more money, to correct it with water changes...