Yep, you've got it. The lowering of the water level encourages the snails to lay the eggs, like mine did, on the side of the tank instead of under the lights where the eggs will eventually dry up from being burned.
You're so smart. My snail has been cruising around by the top lately... wonder if it's looking to lay eggs? :eek3:
I have one snail that likes to cruise straight down the side and will loosen up near the bottom and drop to the gravel. Once though it started to drop from near the top and stuck back on near the bottom. It was just too cool.
Sadly one of my snails got stuck between the heater and the corner of my tank and died. That one never really seemed healthy too but I'm sure it died because it was stuck.
i used to have 3 golden apple snails (and 1 blue one) and they would constantly mate and lay eggs above the water line. I would sometimes save a few large clutches and wait weeks for them to hatch but they never did. Here are some tips from a fellow user gena575 on apple snail egg care:
"Yes you can leave them where they are. You could also gently remove them and place them in a diy hatchery if you are a control freak like me My diy hatchery consisted of 4 strips of styrofoam and a square of plastic craft canvas siliconed together to make a little clutch raft. (www.applesnail.net has lots of ideas in their DIY section) I floated that in a lidded square tupperware. I put that on my light strip so it would stay nice and warm. It took from 13 days for them to hatch IIRC. You'll notice a moldy gross look to the clutch when they are nearing hatching. Ah heck, lemme just post some pictures This clutch was mailed to me so it is 2-3 days old in the first pic."
The DIY nursery
Here the clutch is 11 days old and near hatching
Hatching in progress
The resulting baby snails
Hope this helps. I love apple snails and Im probably going to get them again in the future. Good luck!