PF509 and Ph controller ?

Answer:

Hi Raymond

Although setting up a reactor using a controller can be preferable especially when using the larger models we often find that calcium reactors can work better when set up by monitoring the Alkalinity of the effluent.

When using a controller the internal Ph of the reactor can fluctuate as the solenoid is powered on and off, if this isn't set up correctly CO2 can build up quickly within the reactor or be forced out of the outlet pipe. It is far better to feed the reactor a constant supply of CO2 to keep the internal Ph of the reactor suppressed constantly.

This can be a particular problem with the smaller reactors as CO2 can build up rapidly if thecontroller is set to cycle on and off and inject large quantities of CO2 on each occasion due to over exuberant setting of the CO2 bubble rate.

With smaller reactors we have found that setting a low bubble count and slowly building this by testing the effluent Dkh until it is within the region of 35-50 dkh will give best long term results.

The solenoid can then be set on a timer to shut the CO2 off at night during unlit hours when CO2 levels in tank would be higher due to reverse respiration of the corals and any further in tank suppression of Ph by CO2/low Ph reactor effluent isn't desirable.

If you wanted to you could still use a controller with the 509, simply run the effluent into a small container(about the size of a 35mm film canister) and allow this to overflow back into the sump.
You can sit the Ph probe in the vessel and this will allow you to monitor or control the units internal Ph at the effluent.
 

 As i say though the smaller units run just as well if dialed in by testing the effluent Dkh and should always be set up this way before setting a Ph set point on the controller regardless.
This will allow for a lower bubble rate and longer on/off cycling of the controller and a stable effluent alkalinity without CO2 build up.

Hope this helps Tony