Will this alone raise my pH by roughly .3?
Take a cup of water and test the PH immediately after, than put the cup for a few hours outside and test again.
Although there are other influencers in the tank, that’s approximately the expected the gain you’ll see.
Is this a bad idea? Is trying Kalk a better option? I dont see myself wanting to keep buying scrub media as it is not cost effective.
It’s not a bad idea at all, but it’s permanent changes to your house and not everyone is willing to do so usually.
Kalk is a great option if your Alk/ca consumption is good.
You can either do a saturated solution (usually needs big drum for big tanks and making a new batch quite often, if not daily), or using a kalk stirrer, which while doesn’t take a lot of space and is less hassle - you will need to change the media periodically due to a decline in potency over a few weeks.
Another option would be to look at what you’re doing right now? If you’re dosing sodium bicarbonate, you could switch to carbonate which would bump your PH quite a bit.
Another option is to start using sodium hydroxide as your Alk supplement - it’s basically the same as kalk (Calcium hydroxide), but minus the calcium.
The benefit of using it in place of kalk is the fact that it’s far, far more soluble - no drums or daily batch making needed. On the flip side you need to handle it with caution (gloves, goggles, long sleeves, etc).
I had similar problems with my frag tank and I switched from bicarbonate to carbonate and finally to hydroxide - my ph went from around 7.7-7.8 to 8.3-8.4.
But you really need good Alk/Ca consumption to use any Alk/Ca based solutions - otherwise it’ll limit you.