Spotted Reasonably priced PH Controller?

[limsteel]

I spotted a China Made Weipro PH controller for sale... slightly above $200. With it I can maintain precision control of my CO2 fertilisation.

What to look out for in a PH Controller?

those interested can go and take a look at Y618...

[Cacatuoides]

I'm currently using the above mentioned PH controller....easy to use and set up.....so far so good, controlling PH quite constantly....

[tawauboy]

i would say the ph probe.
the controller's electronics should be okay.

[schema]

Don't just trust the reading, u need to be armed with PH7 buffer solution and chemical test kit to calibrate/verify the reading at least 3mths intervals .

I am using Dupla PH controller set, readings do drift from time to time, even the Hanna test pen oso drift.

Mike

[MikeKoh]

[quote:041e1f2d39="schema"]Don't just trust the reading, u need to be armed with PH7 buffer solution and chemical test kit to calibrate/verify the reading at least 3mths intervals .

I am using Dupla PH controller set, readings do drift from time to time, even the Hanna test pen oso drift.

Mike[/quote:041e1f2d39]

How does this thing control the amount of CO2 injection?

[schema]

Easy as ABC!
Pop in the probe into the water,
Set the desired PH value on the pendant, DONE!

The rest is auto, the controller will turn on your solenoid valve(u must have 1), CO2 will flow.........when PH reaches set PH value, controller turn off solenoid........when PH value goes up......then flip-flop again.

Bad thing about this is the solenoid valve will go clack! clack! clak!, very noisy.
Feedback needed: does any user face this dilemma as me?

[limsteel]

Your PH controller too little tolerant? What is the clerance? If the Clearance is 0... when set to 6, THEN 6.1 it turned on and 5.9 it turn off! It is good in a sense that the PH value doesn;t drift too far... But operating like that, will Soleniod will Fail faster?

what is the best operation clearance (or what is called?)? ~0.5?