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A)In order to distribute CO2 and other nutrients well throughout the planted tank water flow must be strong enough.

B)Increased surface turbulence accelerates removal of CO2 from water.

Purpose of project: To maximize distribution of water flow throughout tank without increasing surface turbulence.

Solution: An under-substrate water-return manifold that transports the water throughout the tank beneath the substrate surface and admits water back to the tank via several strategic “return ports” throughout the tank.

Materials used: Common PVC pipe and fittings

PVC cement

Epoxy or silicone sealant as may be required to adapt

Incoming water tubing to manifold fitting

Tools required: Hacksaw or PVC pipe cutter tool

Total Time: Less than 2 hours.

1) I created a cardboard template the exact size of the bottom of my tank to help with getting the finished manifold to correct tank dimensions during construction.

2) Manifold is not permanently attached to bottom of tank and does not require suction cups or other attachment if situated beneath substrate of around 2 ½” (6.35 cm) or deeper.

3) Certain design considerations such as size of fittings and pipe and & arrangement number of water return outlets as well as the method for connecting incoming (return) water tubing to manifold are a matter of builder preference.

4) A screen “cap” on the water outlets (jets) may help in keeping debris from entering the jets. (Note: I have not had any problem with this issue)

5) Ends of water outlets should extents slightly above the substrate surface, say, 1/4” (.6 cm) to reduce the possibility of debris entering the jet. (Note: Positive pressure from inside the jet tends to automatically prevent admitting debris)

Caveat: This manifold design is now designed, built, and functioning according to expected parameters in my tank, however –
It has never been tried by me before and to my knowledge it has not been attempted by anyone else. While the system is functional, it
is possible (maybe even likely) that certain problems may occur in the long-term, such as plant root entanglements in exterior of manifold,
possible algae accumulation in manifold interior, etc. While some of these contingencies may be planned for and anticipated that does not
exclude the possibility of some unforeseen other problems with this system.

That having been said, it works, and my plants seem to like it and the fish don’t seem to mind it at all – in fact the fish are rather oblivious.

With the simplicity of the thing -- the ease of construction and implementation, etc., and the almost elegant basic design and functionality I was (frankly) just a tad surprised that it had not already been done somewhere, but could not find any trace on the 'net. ::shrug::

The water flow is coming directly off my Magnum 350 Deluxe canister filter's return hose. It does not seem to impede the return flow at all, nor does it interfere with the function of the filter. The water return flow from the jets inside the tank seems to be just about as I had hoped (dumb luck there).

As a footnote, after all the work and planning, etc., I am not expecting the new water-return manifold system to make a huge difference in either the quality or growth of my plants. In my mind it was a simple expedient -- a means to an end only. It just happens to work toward the intended end is all.

FYI, my 60 gallon tank's base is about 13 1/2" X 48 1/2" (34.29cm X 123.19cm). This Water-return Manifold System fits within about 1 1/2" from the front (face) and from the back of the tank, and fits within about 1 1/2" from either side.

Detail (1):

Text White Line Font Schematic

Overview (2):

White Line Black Parallel Diagram

This was my first ever article for

What do you think? Useful?

I look forward to your feedback.


Steve Coach (scoach1999, a.k.a., "Earnest Steve")

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