Gang valve question

[Bill Stock]

I bought one of the PennPlax dual gang valves for feeding CO2 to my RUGF
powerheads. Previously I was just feeding the CO2 to one powerhead, but I
thought the dispersion would be better with two. It will also provide a
backup if one of the powerheads fails.

But I can't seem to get both of the powerheads sucking bubbles at the same
time. They seem to be competing against each other. I can get one or the
other sucking by playing with the control valves, but not both. The valve is
somewhat short on instructions. It says there is a built in check-valve, but
I gather this is on the input and not between valves. There is also some
sort of doodad opposite the input, not sure if it's a control or plug. I
could probably crank up the CO2 to solve the problem, but I don't like the
flow too high, in case the solenoid fails.

Anyone have experience with these valves? Will a pair of check-valves on the
outputs do the trick or is there something I'm missing?

[NetMax]

"Bill Stock" > wrote in message
...
>I bought one of the PennPlax dual gang valves for feeding CO2 to my RUGF
>powerheads. Previously I was just feeding the CO2 to one powerhead, but
>I thought the dispersion would be better with two. It will also provide
>a backup if one of the powerheads fails.
>
> But I can't seem to get both of the powerheads sucking bubbles at the
> same time. They seem to be competing against each other. I can get one
> or the other sucking by playing with the control valves, but not both.
> The valve is somewhat short on instructions. It says there is a built
> in check-valve, but I gather this is on the input and not between
> valves. There is also some sort of doodad opposite the input, not sure
> if it's a control or plug. I could probably crank up the CO2 to solve
> the problem, but I don't like the flow too high, in case the solenoid
> fails.
>
> Anyone have experience with these valves? Will a pair of check-valves
> on the outputs do the trick or is there something I'm missing?


DIY or pressurized CO2 tank? In either case, I don't think you'll have
the airflow needed to make neutral/positive the negative pressure
produced by the powerhead venturi. You would need a check valve in both
lines (so they don't compete with each other), and the existing check
valve is upstream at the input to the gang valve. Actually, 2 check
valves would probably not work either, unless you were to build some
pressure behind them and feed through a very small opening. Try feeding
the CO2 into the powerhead's sponge filter (less negative pressure to
balance against). Note that I haven't tried this and it's all
conjecture.
--
www.NetMax.tk

[Bill Stock]

"NetMax" > wrote in message
.. .
> "Bill Stock" > wrote in message
> ...
>>I bought one of the PennPlax dual gang valves for feeding CO2 to my RUGF
>>powerheads. Previously I was just feeding the CO2 to one powerhead, but I
>>thought the dispersion would be better with two. It will also provide a
>>backup if one of the powerheads fails.
>>
>> But I can't seem to get both of the powerheads sucking bubbles at the
>> same time. They seem to be competing against each other. I can get one or
>> the other sucking by playing with the control valves, but not both. The
>> valve is somewhat short on instructions. It says there is a built in
>> check-valve, but I gather this is on the input and not between valves.
>> There is also some sort of doodad opposite the input, not sure if it's a
>> control or plug. I could probably crank up the CO2 to solve the problem,
>> but I don't like the flow too high, in case the solenoid fails.
>>
>> Anyone have experience with these valves? Will a pair of check-valves on
>> the outputs do the trick or is there something I'm missing?
>
>
> DIY or pressurized CO2 tank? In either case, I don't think you'll have
> the airflow needed to make neutral/positive the negative pressure produced
> by the powerhead venturi.

It been working with a single PH for several months. Nice fine bubbles get
sucked down the uplift tube and create a CO2 reservoir under the gravel.

>You would need a check valve in both lines (so they don't compete with each
>other), and the existing check valve is upstream at the input to the gang
>valve. Actually, 2 check valves would probably not work either,

I suspect you're correct. But I guess there's one way to find out. :)

> unless you were to build some pressure behind them and feed through a very
> small opening. Try feeding the CO2 into the powerhead's sponge filter
> (less negative pressure to balance against). Note that I haven't tried
> this and it's all conjecture.

Thanks.


> --
> www.NetMax.tk
>