I have a controller also, I did this in my pressurized system for a couple
of reasons. I killed all my fish the first time I sprung a leak the tank
pressure went low then dumped the last few hundred psi of Co2 into my tank.
Then there was the time I did not know the tank was getting low and the high
pressure system dumped all the CO2 into my system and killed the fish again.
I know I am a novice I have only been keeping fish for five years now but
the piece of mind from my controller is great. Not to mention I can see the
PH without doing any testing. The hobby is supposed to be fun.
"Bruce Geist" wrote in message
...
Just one point. The PH controller will typically also read out the PH of
the water on a continuous basis. A controller is probably 100 to 120 US
dollars more than a simple PH monitor. In addition, for a controller
based
system you would need a solenoid on your valve unit which is an
additional
expense.

In total, for a controller based system, you are looking at another 150
bucks or so extra cost-- assuming you are going to buy a PH monitor as
suggested by Bob and Tom if you don't get a controller. I s'pose that
will
buy a lot of plants! (I am happy with my set up though..)

As I said in my previous post, get the details on successful,
non-controller
based systems and try to replicate that. The reactor will affect
performance greatly, as will your valve's fine adjustment capabilities.
Tom's configuration suggestion is no doubt a good one. -Bruce Geist

" wrote in message
om...
"Blake" wrote in message
...
I have a 155g tank that I'm getting ready to re-plant. I'm going to be
adding a CO2 system to it and am considering a PH controller. I was
wondering if anyone had any advice as to:

1) Whether this is really necessary
2) Which one is better

Thanks,
Blake

Don't need it and will not help.
Get a pH monitor instead, this is cheaper and has the accurate display
of pH etc.
You adjust the pH by setting the needle valve which will hold a steady
pH in a weel designed system as good as most any pH controller set
ups.

Regards,
Tom Barr