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Re: Aquatic Plants Digest V1 #55
Kevin proposes an interesting possibility. I see two problems however.
If the roots are going to be encourage to grow under a barier, it will be
difficult to remove the plants without them getting tangled and torn
off. This happens when I let giant Hyrgophilla establish too long.
These torn off roots would decay eventually but that may not be all bad.
My real concern in the need for co2. We don't want to aerate as much as
we want to reduce co2 removal. Kevins design would be less expensive
than earlier designs and would be worth a try for somebody.
Unfortunately, to be a valid test would require all sorts of controls and
measurements but it still looks like something worth trying.
> ----------------------------------------------------------------------
> From: Kevin Conlin <kcconlin at cae_ca>
> Date: Mon, 02 Oct 1995 13:51:48 -0400
> Subject: Yet another plant tank design
>
> Having been hopelessly confused by the discussions on substrates,
> cation-exchange capability, and the like, I thought it might be
> interesting to try and eliminate the substrate altogether (hydroponic
> plants are normally grown with bare roots anyway). This led to the
> following design:
>
> Aeration chamber
>
> | |
> --------------- Nutrient ---------------
> | _____________ -> Water Flow -> _____________ |
> | | |____________________| | |
> | | | |
> | | | | | |
> | ------- | | |
> |--- | | ------- Water Line --------------------- | | ----|
> | | | | | |
> | |______ | | |
> | | | Powerhead | | |
> | | | | | |
> | | | | | |
> | | | | | |
> | | | | | |
> | | | | | |
> | | | | | |
> |----- | | ------------2" Gravel -------------------- | | ----|
> | | | | | |
> |_ _ _ | |_ _ _ _ _ _ _ Fine Mesh _ _ _ _ _ _ _ _ _ _ | |_ _ _|
> | |
> | 2" Root Growth Area (no gravel) |
> |_____________________________________________________________|
>
>
> Plant roots grow through the fine mesh into the aerated nutrient
> solution circulating below the gravel. Relatively few nutrients
> (hopefully) will make it past the mesh, through the gravel, and into
> the water. Nutrients that escape will be sucked up by hornwort or
> duckweed or something similar. Oxygen diffusion from top & bottom
> would keep the gravel (or even sand) from becoming anoxic. An
> ordinary canister filter would take care of the water above the
> gravel.
>
> The fine mesh could be standard UGF filter plates (the square interlocking
> kind) or even plastic speaker grill, supported by short lengths of PVC pipe.
> Any open plastic container would work as the aeration chamber, which could
> contain bioballs or something similar depending on the degree of aeration
> desired. A valve of some sort at the outlet of the powerhead could be used
> to decrease the flow rate of the nutrient solution. As for the solution
> itself, just add your favorite fertilizer to the aeration chamber at the
> recommended intervals and monitor iron and nitrate as usual.
>
> Comments?
> - --
> Kevin Conlin Montreal, Canada "We're Canadians. We HAVE to be polite"
> ------------------------------
Regarding co2 control valves:
> > One other more mundane question that came up has to do with setting up
> > CO2 from one welding tank to more than one aquarium. Presume for a
> > moment that although I am not clueless in the physical sciences I know
> > next to nothing about valves or fittings. It is unlikely that I will
> > want equivalent amounts of CO2 injection in each aquarium.
> >
> > My hypothesis for how I will need to set it up involves having only
> > one regulator for the welding tank, but one needle valve per fish
> > tank. So there would be a Y-joint 'after' the regulator, and each
> > needle valve (one per aquarium) would attach to the Y-joint. Is this
> > how it's done? This doesn't seem to scale well, as needle valves
> > aren't cheap. What do people with N (N >> 2) aquaria do about this
> > problem? I'm interested in keeping the number of 50psi fittings to a
> > minimum.
> >
> Yes, you need a needle valve for each aquarium, all connected
> to the regulated supply. In my experience, good needle valves are the
> hardest things to find!
>
> Paul Sears, Ottawa, Canada>
I agree with the earlier post (sorry I don't save most of these so I
can't recall who suggested it). The low cost way to run multiples off one
co2 regulator is:
tank -- regulator -- needle valve -- airline tubining -- cheap air
control valves.
I have operated two tanks from one regulator and it works fine. Only
problem is monitoring pH or co2 levels in all affected tanks and getting
a proper balance. It takes a lot of messing around but it can be done.
I like using the squeeze clamp to control flow better than the aquarium
"needle" valves but a good valve is cheaper than the hi pressure needle
valve of the co2 system.
It would be possible to run multiple electronically controled tanks from
a single tank by using a manifold off the main co2 tank that would feed
multiple solenoid valves on the manifold. Back to big $ for all the
solenoids and needle valves, but it would be a better long term solution and
less risky.
It doesn't take much error in valve setting to drive pH down to the point
of losing fish. For this reason I went back to a single aquarium off the
co2 tank. -
Earle Hamilton from northern Michigan where coral once grew