Does anyone know of a very small circulation pump which will supply very gentle water movement in a 20 gallon long tank? I need the very gentlest water movement possible and the smallest of circulation pumps or powerheads.

On the whole I think a circulation pump will be better and smaller than a powerhead but I need some advice as to which of them will supply the GENTLEST water movement. I've got a 20 long river tank set-up and do not need the kind of power you need on reef tanks. Just a mild gentle current over the riverbed is what I need.

Does anyone know which of the pumps out there will be best?

I would NOT try a bicycle pump or a short pump but Instant Ocean (Aquarium Systems) have the Maxi Jet pumps that are fairly small and Supreme (EG Danner) has the Mag Drive pumps. I'm not sure how small the come. Check Out Champion Lighting.com. They have a big selection of pumps. Also Little Giant Pump comp. has the small fountain pumps. There is a place on Staplesmill that carry the LG pumps. They are CSC Equipment comp. they do pool stuff. 266-9803

I don't know Deb, I've been looking online at several forums, and sites and can't find anyone mentioning issues with bicycle or short pumps. You think Mark is factual or just responding with heresay?

LOL Ron! I think Mark is pulling my leg on the short pump. or maybe he's yanking my pump chain? *lol* Don't know. I've checked out Champion lighting and found some interesting small pumps. Don't know what I need yet but there is more out there than I thought. Had not even heard of Rio, for example.

What about those Hagen internal "stingray" pumps? I have one I can send your way if you want to try it first. It can be suction-cupped to the glass or just placed on the bottom. It seems pretty gentle to me, with a diffused outflow rather than a jet.

I have a fluvall U1 that is rated for 65gph but can be adjusted to slow down the flow. Check them out

I am sure I have the very smallest - I was using in a 2-gal at one point before I decided to make it no-tech. I'll dig it out for you.

Thanks!

Hmmm...a river tank with minimal current. I think that might be a first for me.

An AquaClear20 should work. I ran a couple on my rivertank when it was a 20l. I've upgraded to a 30breeder and upgraded my powerheads as well. Getting ready to upgrade once more to a 40breeder.

Another viable option could be a ZooMed 501 canister.

James, hi. Welcome to the site.

I should have been more clear - it's NOT a rivertank. It's simply a slow-moving stream of water over a bed of rocks and sand. I used the term "riverbed" to describe the morphology of my set-up. The minimal current is essential to my stocking plan.

Powerheads and bulky HOB's will move too much water and be far too big, physically, for what I want. Liz's "Ray" is the best choice so far from what I've seen (and I've been all around the nano-circulation pump block!)

Thanks!

Ahhhh....I see now.

I would look at the zoo med then. Comes with a small spray bar. You can position it to where the flow directs on the glass if the current is still too much.

Annnnnnnnd....as yet another option...you can still use an HOB. Make a DIY diffuser from a Gatorade bottle and place it on the out flow. Will drastically reduce the current.

Live plant filters such as moss or riccia work well too. I have a riccia mat on one of my HOBs. I'll have to get a pic for ya.

Yeah, I'd like to see the riccia mat! My lighting might not be quite right for it, but it's something I'd like to try.

I should mention that this tank is filtered with plants only and does not have a mechanical filtration system as such. The plants are the filter. My style is very low-tech which is why I opt for the simplest equipment possible, always. *lol*

I move the water around the plants manually every day but a gentle mechanical option would suit better. If it were the right style I'd add a small filter sponge too.
thanks for the help!

i'll snap a pic of the riccia.

by your description....a spray bar is exactly what you want.