Re: Yet another plant tank design

On Tuesday, 3 October 1995, David Whittaker wrote:

> Are you going to build it?

I have a 33g tank that I'll convert if I have to tear it down for some
reason.  At the moment, this low-tech tank (UGF, Aquaclear, 20W cool white,
20W warm white, no CO2) is pretty good at growing crypts, so I won't be
changing it anytime soon.  If you can convince my wife to let me build
a 14'x2'x2' 400g tank downstairs I'll try it there.

Charley Bay wrote:

[ASCII art deleted]

> Kevin, good design.  I'm doing this now.  I am very happy with it.  I
> would do the same thing again.

The two designs differ a bit in that my system (which, in fact, was
derived from your system, but I couldn't remember who the original
designer was) keeps the water and nutrients in the open space below
the substrate circulating and aerated.  Like yours, it attempts to
deliver nutrients directly to the roots, keeping them out of the main
part of the tank where they would contribute to the growth of algae.

> With this setup, I dissolve my Dupla tablets into the "nutrient rich
> bottle", and I put the bottle on TOP of my tank and let gravity dump 
> the solution directly into the substrate.  Simliarly, I can drain water 
> out of the substrate (to test nutrients, whatever) by lowering the 
> bottle below tank water level.

I like the bottle idea.  I might try an IV bag to drip nutrients into
my system for really uniform dosing and minimal effort.

> This is a 180 gallon tank, and I have full view of the bottom.

Being able to directly view root growth really appeals to me.

> The
> plenum is supported by egg-crate, covered with 2-3 layers of nylon 
> screen.

The egg-crate is a very good idea.  There's a plastic mesh made for
cross-stitching that's a little more robust than ordinary nylon door
screening.  It might hold up better when plants are ripped out.

> The substrate is 2 mm sand (sandblasting gravel), and layers 
> of peat and vermiculite in the bottom 1/3, if you were wondering.  

I was planning to use plain gravel or sand.  The gravel is not intended to
encourage root growth (although roots will certainly grow there); it's
more to restrict the movement of water and nutrients between the two
parts of the system, and of course to look good.

> The tank is well-planted, thanks to George Booth.  (HEY, GEORGE!  
> Nothing died!  My CABOMBA HAS RUNNERS!

My cabomba was eaten alive by the gouramis...  Not a pleasant sight.

> The setup was incredibly cheap (except egg crate was $14 for a 2x4
> foot sheet), and it is incredibly cheap to operate (gravity).  Most
> of the time, I simply do nothing:  I dose nutrients every now and
> then, but otherwise leave the tubes turned "off" and no flow occurs
> in the plenum.

Both systems should be very inexpensive to build and operate.  Very important
when you're paid in worthless Canadollars.

> I have already designed a commercial version of the same system that
> I would use to propagate plants at a commercial level.  The only 
> difference is that I have made modifications to the 
> framework/infrastructure to allow me to mechanically "prune" off 
> roots that grow through the screen and into the plenum.  Thus, the 
> plenum can be directly accessed for maintenance or cleaning.

Another difference here.  I'm trying to get the roots to grow in the plenum,
not in the gravel, so there would be no pruning at all.  I have no means of
accessing the plenum, although dead roots from pulled-up plants might be
cleared out by cranking up the flow rate of the powerhead temporarily.
Perhaps I could have a trap-door in a corner of the tank (or just wide
UGF uplift tubes) for sending in a siphon.

> [embarrassing part]:
> I've heard of people that come up with ideas, use them, and somebody 
> else patents it, and the author can't use it anymore (the courts don't 
> care who the author is).  I really like this design, and have 
> commercial plans.  I don't care who uses it, I just want to be sure 
> *I* can continue to use it (I don't want anybody to patent it and tell 
> me I can't use it anymore).  Is this an issue, or am I just paranoid?  

If you can prove prior art, then you can use someone's patent with
impunity.  These postings constitute prior art.

> I'm not paranoid!  I'm perceptive!  Who said that?  What?  I hear 
> voices, but I don't do what they tell me.   :^>

I think you've been living in the high mountain air too long, or you're
growing other types of plants that you're not telling us about.  Try
supplemental O2.
Kevin Conlin   Montreal, Canada   "We're Canadians.  We HAVE to be polite"