So I read some more on the balancing act of TA & Acid. Turns out, I was doing it wrong. I could have saved quite a bit of money on waaaay less acid and soda ash. The secret? Aeration.
In doing this over and over, I noticed the following: Adding acid drops TA & pH (duh). Adding soda ash increased pH … and TA. Not what we want.
We needed a process to increase pH but not TA. Enter Aeration.
Using a spare pool hose, a shop-vac, electrical tape, and some 1.5” PVC I had lying around I hacked up a ‘ghetto bubbler’. The exhaust of the shop-vac (a high-velocity low-pressure flow) is routed through the pool hose, into the 1.5” PVC which hangs over the side of the pool and is clamped in place. The parts of the PVC submerged under water are drilled every 3/4” or so with a 1/32” drill bit – on the bottom of the pipe. This creates a ‘air stone ‘ effect out of the PVC. I used electrical tape to make the hose fit snugly into the shop vac and the PVC bell end I used. After proving this process worked, used the 3d printer to make some flexible TPU couplings that fit nicely over the hose ends and adapt to the proper diameter, so I don’t have to ruin anything with permanent fixtures or tape. :-)
After two and a half days of bubbling, my pH went from ~5.0 to 7.6. PERFECT. I did not run the bubbler overnight, but I did redirect the return hose to ‘jet’ water and cause turbulence 24/7.
The pool has had perfect water for a week, albeit a bit low level of water. And it keeps getting lower because you know, splashing, and evaporation. That’s OK. We can deal with that.
Added bonus: the shop-vac exhaust air is warm, and raises the pool temperature. :-)
So this morning I set about to raise the water level about 3 inches. I’m filling from the ‘softened’ water we use inside, although I’m quite sure my softener needs a recharge now.