Bottom drains are excellent. But for a 300 gallon, established pond I would just use a shop vac a few times a year or a siphon or pump.

You need to remove the gunk, but the fact you have carpet algae without string algae suggests the pond is balanced. So I would just concentrate on removing the solids every so often.

Regards,
Lisa

Right on Lisa!
Great advice!
"Horton"

Thanks Lisa now time to go buy shop vac!

What about adding some trapdoor snails to help clean the bottom up?

OK, Anyone have an answer about the trapdoor snails? I would try that...if there are more pros versus cons.
I don't have many problems, don't want to start any new ones :)

S

Sarah,Trapdoor snails are interesting to watch as they slowly slither around eating everything before them.
But in as much as Trapdoor snails do eat the waste/algae off the bottom and sides of a pond, I figure you would need an army of them to really see any difference in the accumulation of waste/algae. They will also lunch on your pond plants.

One problem with Trapdoor snails, (and the large water snails in general) is that when they die and they are hidden in plant pots or in liner folds, they rot and stink to high heaven.
They could pollute a small pond if left in there after they die.

Some Koi breeders use hundreds of Trapdoor snails in their ponds, to help eliminate the fish waste. But those Koi breeding ponds do not have plants in pots where the snails can keep out of sight.

They are live bearers and produce young snails about twice a year.
"Horton"

Here is a link that might be useful: Good article on Trapdoor Snails.

Dear Okiee,

Please, oh please don't waste your time and energy on a shop-vac. I used to do it this way, so I know that even with a 300-gallon pond, the constant emptying will break your back. For a few more dollars you can get a Flotec 1/2 hp utility pump at Home Depot, attach a few pipe fillings to the inlet hose and a length of pvc pipe, and wah-la...your very own pond vac that operates continuously, rather than putting up with the auto-shut-off of the shopvac when it gets full. I actually used fittings to attach my footed vacuum nozzle from my old shop vac to the end of the length of pipe, so now I can truly "vacuum" the floor of the pond. A lot less work, less bending over, quicker, less to clean when you're finished. Good luck,
Jan