Hi there - So I'm yet another frustrated Baquacil (my pool store goes by the Revacil brand name now...) pool owner, who's been struggling to maintain a good looking healthy pool. Ive been reading all these stories and I pictuarize myself in each of these. So, I have a 20X40' 30-33,000 gallon pool (believe me, I'd be happier with a smaller pool), vinyl, sand filter etc. Opened it a couple of weeks ago, managed to get to an OK looking blue cloudy state, which lasted a mere week, after which starting this week its all green again, unbelievable ! I've had the same issue the last 3 seasons ever since i moved into this house. Its really nice to see so many have already successfully converted to a Chlorine pool. I've now finally made up my mind to join in as well. Ive been reading all of these forums...which has been extremely useful. I still have a few questions tho - 1)will it help to first empty out atleast half (if not all ) of my pool water, then start the conversion process? or it doesnt really matter. My thot here is that it may be quicker/more economical to treat 15-20K gallons vs 33K, plus I'm desperate to see the bottom of the deep section (which ive never seen) to make sure no algae is left behind during brushing/vaccuming. But then there's the cost of refilling (approx $60-100). 2)I've just changed my sand filter 2 weeks ago and wouldnt want to spend another $175 to the pool person to change it again. Is there any way by which i can still use this sand during and after the conversion..?..will really appreciate any suggestions...thanks