I've been kicking this idea around for the pas couple of years. One a handful of occasions I even implemented the idea, or attempted to do so.
Desired capability: To vacuum the floor of my stock tank (of course other types as well) with a hose that provides better suction than a siphon.
Please scroll to the bottom "TL;DR" portion of the post if you wish to skip the backstory.
At present, I have a basement w/ a "trap" that is just about 8 to 12 feet below my tank. In the past, I used to hook up a hose to the tap water faucet (same level) and use it to add water to the tank as well as to prime the siphon. Once the hose was primed (full of water), I could take the faucet-side and stick it over the toilet bowl for a slow flow. It was adequate for partial water changes and larger water water changes given enough time and patience. For vacuuming, the pressure was very weak and barely adequate. Eventually, I came up with the bright idea of running end of the hose to the basement. It's really simple, I open a cap on the "trap", and stick a PVC pipe into it which stands vertically w/ a lean. Then I stick the hose into the top of that pip. This allows for two things. One, it prevents me from putting that hose directly into the opening on the floor which prevents contaminating the hose.
By "hose" I mean clear flexible tubing -- vinyl "food grade": "ATP - PVC18-14ANA Vinyl-Flex PVC Food Grade Plastic Tubing, Clear, 1/8" ID x 1/4" OD, 100 feet Length".
This works great for water changes and adequately for vacuuming solid waste from the floor of the tank. However, I have to make multiple passes since it takes time for stuff to settle once it has been kicked-up. This is a fine excuse to take my turtles out of the tank, but I don't like doing this unless the weather is good so that I can let them get natural sunlight in the backyard screen room.The other big problem is that it gets clogged by scutes. Still, this has worked better than my first attempt at using a pump to vacuum. At the time I merely used a pump and two tubes to suck-up waste. Unsurprisingly, the impeller got clogged very frequently. This lead me to think the "ideal" solution would be have a pump with sharp blades in it, like a garbage disposal. Alternatively, I may be overlooking some simple physics...
Side note: I did buy one of those cheap vacuums on amazon. The theory seemed sound, but it's "bag" filled-up quickly. Another thought would be to stick some kind of "filter sock" between the inflow on my filter (or generic pump) in order to prevent the impeller from getting clogged.
As of right now, my "best" idea is to find some combination of tubes of different diameters... or maybe just one tube of a wider diameter?
TL;DR: My newest idea is to use a wider diameter tube from the tank to the basement for vacuuming by way of siphon. In order to add water to the tank using the same tube, or to merely "prime" the tube, I would use an adapter on the faucet-side since I'm currently equipped to attach a 1/4" outer-diameter tube to my faucet (1/8" inner). It is my hope that the wider tube/hose will be less-prone to clogs (hopefully the issue will be all but eliminated). However, if this is not a viable option for any reason that I am currently overlooking, I'd hate to waste money on such a tube (although I only nee 25'). Secondly, if this solution isn't good... I suspect that it may be worth revisiting the "pump" idea. Is there a way to hook-up a pump in such a way that it helps "pull" water while allowing solid matter to bypass it trough a parallel tube?
If these ideas are not viable, I have one more method for which I did have pretty good success with but have avoided for good reason. On one occasion I hooked a tube up to the inlet on my filter and essentially used my canister filter as a canister vacuum. It worked really well but it also meant that I would have to clean the mechanical filter media more frequently if kept using this method. Still, if all other ideas come up dry... maybe this is an opportunity for me to get a fancier canister filter such as a Filstar FX-5[/b] or better and re-purpose my "Sun Sun" as a dedicated "tank vacuum".
Thanks for reading on behalf of Paffie and Squirtle.