Best way to avoid kalk overdose?

[chaostactics]

So im going set up my kalk reactor and want to avoid an OD. I dont want to lose my ATO abilities if my pH goes too high. So normally ATO vessel, to kalk reactor, to sump. But i want to set up a way to have water bypass the Kalk reactor if my tank pH climbs to high (as determined by an Apex).

 

How do i do this? simply, cheaply, and reliably (i know sometimes you have to pick just two of factors. 

 

Im guessing something with a solenoid? Two pumps for water supply? What?

 

[seabass]

A solenoid works well for short changes (like normally always on, and occasional but short forced offs).  However, maybe that's not the best scenario for your setup.

 

I'd rather you setup a cheap dosing pump to drip kalk in.  Some people only do this at night, but I think you can have your Apex just stop it whenever pH gets too high.  Note that pH probes need regular calibration.

 

I'd probably run the auto top off independent of your kalk reactor.  It would add any additional water needed to maintain your water level.

[jservedio]

How much Kalk are you running and in what sized tank? In my tank, I run slightly more than 25% saturated lime water and with my evaporation rate, I am only dosing getting about 0.5dKH per day, so I just run it right through the ATO.

 

Some days I get more, some days I get less - but the alkalinity stays somewhere in the 8.4 and 9.2 over the course of an entire 5g bucket, which lasts somewhere between 15 and 20 days. If the Alk starts creeping up much over 9, I'll dump a few cups of RODI in the tank to slow down the dosing and if it starts creeping too low I'll do a bigger water change. The kalk leaves little rings in your ATO bucket every time the ATO kicks on, so it's very easy to monitor.

 

Having your alkalinity stable is far more important than your pH - so if you are going to run a pH probe and let it control your Kalk, you need to have an alarm on there.