Snails can eat holes in the leaves. I always thought the clear/jelly stuff was dead/decomposing snails, but I might be wrong. You might try putting some lettuce leaves in your pond and then taking them out when they have the snails on them.
Also....be sure to thin your waterlily every couple of years, and fertilize every 3-4 weeks in the spring/summer season.

okay so snails = bad :( I liked them too! lol .. I just thinned them today..well, split it in half. I couldn't believe how huge the rhizome/mass of roots was just from one bulb last year ! Now if I did it right I will have two beautiful bloomers this summer! :) Thanks for your input!

You're welcome chubbypoptart! Its really amazing how much those guys can grow, even in just one season! Unlike lotus, you can start to fertilize them early on.
What I usually do is just cut out 1/2 of what's in the pot and fill that area in with soil. I find that easier than pulling the whole plant out and dealing with it.
Those waterlilies are really hardy.
Enjoy all the blooms this summer!

The jelly like substance on the underside of the leaves are clusters of snail eggs. I also suggest placing lettuce leaves, cucumber slices, etc in the pond at night and then removing first thing in the morning. Also, when you find a cluster of snail eggs you might want to scrape them off. Snails are extrememly hard to eradicate. Good luck!

Thanks for the suggestion of the lettuce leaves. I'll try it. BTW, be sure you don't put the leaves in the compost pile. The snails will love it and increase rapidly to take over all your garden in short order. I would put the leaves, snails and any scraped off jelly(definitely eggs) in a Ziploc baggie. I might even put in a couple of tbs. of salt to hasten their demise.

Lift up any loose object such as wood, stone, flower pots or ornaments especially after sunrise and you will find lots of snails looking for shelter. They love hosta and can destroy a large plant in short order. A good trap is several layers of wet newspaper laid on the ground in the evening. Lay a rock or brick on it to hold it down. There well be snails under it in the morning. I used to go out around 11:00 PM with a flashlight and a jar of salt water to collect them and slugs as they attacked my lilies, hosta and callas. They can spread several plant diseases that really play havoc with almost any plant. Check any new plant that you get. They hide in the pot going through the drainage holes.

Aquatic snail eggs and snails will die in your compost heap. No problem putting the leaves in the compost. A turtle will eat the snails. You could consider getting a red eared slider baby from a pet shop. Weather loaches AKA Dojos will also eat the snails.

Kalevy, they don't have to be aquatic snails. The regular old garden snails show up in my pond all too often. After a rain they climb the sides of the Skippy and there will be dozens of the snails and hundreds of the jelly clumps of eggs scattered over the sides and the filter material even where it is submerged. They like the wet.

I did have an aquatic snail the first year I had the pond. It was always outside the pond on the ground rather than in the water. What I see in the photo is a common garden snail.

The red eared sliders will definitely control the snail population but they are torture on the lillies. I have had to put barriers around mine. The turtles like to root around in the pots and will also eat the new shoots. I use a ring of checken wire around the lillies allowing the fish in but keeping the turtles out. I have found once you have snails you always will, but beleive me they are less damaging to your plants than turtles.

The clear jelly is snail eggs. I try to pick off the pads with the most and toss them. I've never been able to completely get rid of snails.