My pond is much smaller-only 600 G-so using a wet/dry vac is easier for me. I just have the standard attachments that came with it (though that might have been a "deluxe" model.) I use the smaller diameter hose with the flattened attachment that's about 5-6 inches wide to vacuum the loose stuff on the bottom. (Don't use the filter for wet use.) The canister fills up after a minute or two and will stop sucking. I then turn it off and empty the water to the side of the pond. I do the worst areas first and move slowly. It seems a bit tedious but I do finish my pond in 30 minutes or less and it doesn't disturb the fish.

So you don't buy a special attachment for the hose. I was also thinking that my hose was pretty short, I'd have to float my vac canister if I was to try to get into my bigger pond pool and do the bottom.

Do you find it to be a two person operation? Where do you put the vac canister when you have it running? Mine always wants to fall over or come forward.

Does it matter if it is on high ground or low ground?

Would it work to just put a hole in the side of the shop vac's canister if I'm willing to turn it into a PondVac, exclusively? This way the water could just run out and you wouldn't have to stop to empty it, would you?

I haven't used the shop vac in my pond, but we used it with our above ground pool last year. We were able to use the shop vac to get it started and then disconnect the hose. Basically just worked as a siphon. Might address the issue of the shop vac falling over or having to float it. You could also get a hose like you would use for cleaning a pool. I may actually try that on my pond this year.

I also use the siphoning method. That way you have room to do a partial water change. I run the 'fish water' into a flower bed for natural fertilizer.

When you vacuum, how do you avoid sucking up the dragonfly nymphs? When I net out the leaves and junk, I occasionally come across a nymph and put it back in the pond, but they are hard to spot. I'd hate to just water my lawn and flowers with them. . .

I use my long net and periodically put on the hip waders if there's string algae on the bottom. I do have an Aquarium Python which I wonder if could be used. Only thing is they work on the principal of suction while tap is running and I can't run tap water into my pond due to the chloramines. Could maybe attach garden hose to it though and let it run onto the garden. I've used the shop vac too but mine only holds 6.5 gals so after 30 secs I'm dumping the cannister.

Hi Jalal,
The Python does not run the tap water into the pond when you are using it for suction so you are fine with that. I will hook the python to the tap to get suction started then use gravity suction for the rest, once the hose is full of water. Only problem is that the hose plugs up if you get any larger bits or clumps, I have a nearby pine that drops needles that turn in the hose.It works pretty well for a small pond or regular maintenance but is tedious for spring cleanup.