Adding Borax? pH drifts high and TA low

[JoyfulNoise]

I think around 7.4 - 7.6 we have grandkids that like to have a little go now and again

Most water with any appreciable amount of carbonate alkalinity in it doesn’t typically like to be at that low of a pH. The rate of outgassing of CO2 from water increases as the pH decreases so if you try to target a low pH, you simply drive off more CO2 which raises the pH right back up. In other words, you’re swimming against the tide.

Try to maintain a TA of around 50ppm (40ppm is ok) and don’t lower the pH any lower than 7.6. Wait until your pH is up near 8.0 before you lower it. This should keep your acid addition frequency lower.

As for CH, 90ppm is a bit low but anything above 125ppm should be more than adequate for keeping foaminess down.

 

[Matilda]

Great, okay that makes sense. I'll give all your advice a go and thanks again !