Recommend me a PH Controller

**Nick** · 29th Dec 2001, 17:20

Thinking of buying one before I spent the last drop of my bonus. Budget maybe about $300+. Recommendations, please!

David, that time you say the PH controller can dunno do what, something like cut the supply of something.... during the 1st planted tank demo. Care to rephrase it again? I want to know what you mean.

**LiquidFX** · 29th Dec 2001, 23:22

Correct me if I am wrong, but its cut the supply of the CO2?

**David** · 29th Dec 2001, 23:25

hello nick

looks like you are going to take the plunge into a PH controller huh?

Basically the purpose of the controller is to minimise PH fluatuation through CO2 injection and by doing so, it also keeps the dissolved CO2 level in the water level at near optimal levels.

With a PH controller, a PH crash is virtually impossible as most controllers are programmed in such away whereby the fluatuation tolerance is at +/- 0.1 PH. This means that, for example the desired setting is at 6.9....injection will occur at 7.0 and will stop at 6.8. If by any chance the amount of bicarbonate fails to buffer and drops to 6.5, there will never be any injection at all as opposed to mechanical injection using soilnoid and timer, which will keep the injection going till the timer turns it off. If there is a system error, a good PH controller will cut off any injection as well.

All things said and done, a PH controller is only as good as the aquarist using the device. A good understanding of the relationship between KH and PH is still essential. This means that if the water KH level is at 6 and the preset PH is at 6.5...there will be an over injection that may cause fish death eventually. Experience will also play a part as fishload and size comes into the equation and adjustment needs to be compensated by the aquarist.

Brands to consider are

Dennerle, Dupla, Ehiem, JBL, and recently AZOO....before buying, briefly go through the instruction booklet and also check the electrical socket is suitable for your soilnoid electrical head....the probe must be sealed with a waxed cap with distilled water.

if you need more info nick let me know.

**Nick** · 30th Dec 2001, 01:21

I get what you mean regarding the kH-pH relationship. Seems that with the pH controller, it is even more important to monitor the kH than before. Thanks anyway. Will survey first before buying.[

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**sherchoo** · 30th Dec 2001, 10:27

To monitor kH is not that difficult as compared with pH. kH only changes usually during water changes and if add some other things like bicarbanates. Adding water during to replace evaporated also does not alter the kH. So it's don't really pose a big problem. Besides, monitoring your kH should be done even though you're not using the pH controller.