opening pool for summer from forest green swamp

[rweber12]

I believe I didn't get the top back on secured tightly enough and it just drained itself due to the lack of suction.. I but the garden hose down the pipe it pulls from the pool and let it run for a while and put the top back on and sealed it tight and it has been running well for a few hours now.

I've run out of the liquid chlorine again. I plan on running to the store to buy some more but I have some giant 3" chlorinating tablets that I purchased from Menards. The active ingredient is 99.3% trichloro-s-triazinetrione with 89.0% available chlorine. Could I use these? The previous owners swore by these and just said to drop 3 in the skimmer baskets once a week and I'd be golden.