Loaches Online Forum

I have been wondering about the river tank manifolds that seem to be very popular. How many of you use that method for your tanks? Are there any pros and cons you would like to share?

I have one 20 long with an official RTM (I just made that up, is that OK for our glossery?)

It was REALLY easy to put together (but them I have been building irrigation systems for mumble-mumble years) PVC is SO easy to work with!
I put mine together without glue. Everything holds just fine.

Use the coarsest sponge that you can over the intake. They plug up really fast, and the finer sponges plug up even faster.
The Aquaclear filter sponges are about the finest sponge I would try to use.

I have been using Aquaclear powerheads because that is what I have plenty of, but their bottom piece does not secure very well to the body. I need to also use the suction cup holder to secure the PH in the tank, and it just sort of sits over the manifold. It is secure enough that no fish can get it, but it won't just sit there on top of the PVC pipe without being stabilized by the suction cups.

Thin wall PVC will work just fine, and has a larger interior volume for moving the water. In my small tank I used 1/2" PVC. I would use larger pipe and more than one PH/sponge for larger tanks.

I also have the filter set up to add to the flow: Intake near the RTM intake, filter outlet at the other end of the tank, over the power head. (Small canister filter, one of the Eheims)

I also make intake manifolds with a similar concept for most of the filters. Several sponges on a branching PVC set up.

I use a RTM (I like it Diana ) in all of my tanks which are at least 4 feet in length or longer. I highly recommend building one, especially if you keep loaches. I use 3/4" pvc, typically three full length pipes with two up-pipes on each end for intake and two on the other end for powerheads. I too use Aquaclear powerheads and HOB filters; additionally I have a Rena cannister filter but it is currently not being used anywhere - I'm working on a future project which will involve the Rena.

do a search

thanks to Diana and Rubix for you helpfull comments.

This setup sounds great. Has anyone got any cons?

and newshound, that was not a very helpfull...

Only negative I can think of the the presence of the PHs in the tank. They can be camouflaged with rocks I guess. I do not mind them, but some people might.

I have a 20L w/RTM like Diana and I love it ! My hillies do too.The only con I can think of is that the powerheads can add a good bit of heat to your tank which can be a problem in the hot months.

plaalye wrote:I have a 20L w/RTM like Diana and I love it ! My hillies do too.The only con I can think of is that the powerheads can add a good bit of heat to your tank which can be a problem in the hot months.

oh, yeah. I didn't think about the extra heat. Thanks for the great comment.

I hope to one day set up a river tank. It sounds like the manifold is pretty great.

cons I've had-
You need to use extra substrate to keep the manifold covered.

Doesn't eliminate the need for filters. The manifold and powerheads just adds extra water flow. A 6ft tank will still need atleast 2 large filters.

The inside of the pipes will get dirty. After about 6 months, when you turn the powerheads off, then turn them back on, a lot of gunk will start coming out of the pipes. (The filters should clean this up)

The powerheads will add extra heat to the water. This is good during the winter, but during the summer the heat can sometimes be difficult to control.

The powerheads will add noise and vibration to the water. I might not hear or feel it, but the fish will.


The positives that the additional water flow will provide definately outweigh all the so called negatives.

So do you guys ever clean the pipes somehow? Maybe a reverse flush or something?

Oh, and Do you guys think this setup would be appropriate for Danios?

And.. Is it important to have a "river" flow for Clown Loaches, or are they just as good in a more standard type setup? I am just curious.

Many Danios, and Clown Loaches come from somewhat faster moving water than a standard set up, but it does not have to be a RTM. Maybe half that. One or two powerheads instead of 3-4. Perhaps the Koralia type of PH, with its more diffuse water movement.

I would aim for around 20 times your tank volume per hour in water movement for the 'good water movement, but not quite a RTM' type of fish.