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Re: CPVC UGF & Spray Bar



"Robert Welch" <rwelch at ionet_net> wrote:

> I've been "lurking/observing" this list for some time now trying to get up
> to speed on the latest to do a planted tank.  I am returning to this hobby
> after some 20 years and a great deal has changed in that time.  Perhaps this
> is a question for Tom Barr specifically, but I thought I might as well throw
> it out to all.  I am setting up a planted 55g tank with a Flourite/Sand
> substrate.  Tom's approach of providing flow to the substrate via a CPVC UGF
> is one I am going to incorporate since I am starting from scratch.  Even if
> I find I don't need it - it will be in place if I do.  There is also
> considerable talk (on other boards as well) about limiting the amount of
> water current in planted tanks by using a spray bar.  While I was
> constructing the CPVC UGF, and in particular the riser tube, I thought, why
> not integrate the spray bar with the UGF?  That is, use two risers (at each
> end of the tank) and connect them with a horizontal bar just below the water
> line to act as the spray bar.  The entire apparatus would be subject to
> pressure/flow from the filter discharge.  It will take some experimenting to
> determine the number and size of holes to place in the horizontal bar versus
> the UGF but it should work.  Just guessing I would say I want about 80% of
> the flow coming out of the spray bar and the balance going to the UGF.  Has
> anyone tried this variation or have any comments?
> 
> Bob Welch

Bob,

When experimenting, as you say, to find the desired balance, how do you 
measure how much water is going into each way ? And later, how do you 
control the balance ? I've benn fiddling with this sort of thing for a 
while, and the only reliable way I found to control how much water goes 
into the substrate pipes is to have the raiser tube have the open end 
above the water surface. Water can then be poured in with a split line 
from the filter or an auxiliary pump. Also, too much piping directly 
connected to the filter output will increase the head significantly. 
Because of that, and because spray bars tend to clog easily and so fall 
into my class of "high maintenance devices" to be avoided, I entirely 
gave up with spray bars. I use now just larger bore pipe at the filter 
return line. It works by reducing the water velocity. The larger the 
bore, the "tricklier" the filter output gets. The output nozzle is just
a short piece of 3/4" PVC pipe pointing downwards at a 45 degree angle,
just below the water surface. Nothing inside the tank, nothing to clean.

-Ivo Busko
 Baltimore, MD