Just wondering how everyone does their water change? Is it just, siphon water out and then refill with room temp. water and then at he necessary amount of prime to it? Is stability needed or is that only for the brand new cycling of tanks? Also, for the prime, do you add the amount correlated to your water change or the volume of the whole tank? So say you do a 25% water change on a 100 gal, do you add suggested prime for 25 gal or for 100 gal? sorry, new to all this and want to get everything right. thanks.