Snails and worms?

Hi all,

I have a male betta and an oto cat in a heated 10 gallon tank. (Normally the temp is fine, but the heater messed up, so it's been too cool. We just bought a new one.) I don't have a test kit for the other information, but we set the tank up in January and use Prime, so it should be fully cycled. It has a TopFin small filter in a Whisper 5-15.

I used to keep aquariums several years ago, but it's been awhile and I'm just getting back into it.

I bought two moss balls and put them in the tank a couple months ago. I soon had snails. Should've salted the moss balls first.

The seller insists they didn't come from him, so I don't know what they are. It's the only place they could've come from. (The driftwood, added around the same time, was soaked in boiling water.)

Three or so weeks ago, we added some plants to the tank. I killed the anacharis we'd originally put in there when we started the tank (initial poor lighting) and added something else recently. I can't remember the name. But we could see snails in the tank at the store, so even though we already had a problem with snails in our tank, we salted and rinsed those plants.

Now, we have tiny worms AND snails that are consuming my catfish's algae pellets.

My husband normally vacuums the tank once a week and does a ~40% water change, but we have had work/health issues that have kept us from as thorough cleanings in a couple weeks. We are trying to figure out the best schedule now to reduce/eliminate our problem. We use Prime following each water change, and no meds for the fish.

Can anyone tell what the snails and worms are? Maybe common pond snails? The worms are gross and probably both multiplied because of the algae pellets, but I'm mostly concerned in case they're parasitic. Some float in the tank, and many are on the glass. They are too tiny to see the details of.

I would put in assassin snails for the brown snails, but I'm afraid they'd kill the catfish.

Tl;dr: What are these worms and snails, and how can I get rid of them without endangering my tank?

Both pests can be seen in the picture. I can add more if necessary.

Thanks!

http://imgur.com/2LlvdH6