Carl,

First of all, take a deep breath and relax. I'll let you know the probable effects of what you did and how you can fix it and others can chime in if I screw up or to give further assistance. You and your pool will get through this just fine.

I calculate that with your pool numbers the 2 gallons of acid probably lowered your pool's pH down to 6.7 so that is not something to be overly concerned about. Since you are already down to that pH, you might as well follow Ben's procedure for lowering alkalinity where you have already started with the part about lowering pH and can start the aeration process and watch the pH rise. When the pH rises to the point that it's measureable on your test kit (i.e. at the level one higher than the lowest level on the test kit), then you can continue to aerate AND add acid to keep the pH low (per the procedure). Monitor your TA during this process and watch it drop until it reaches your target which should be around 100 (assuming you stop using Tri-Chlor tablets -- more on that later).

Your CYA level is on the low side IF it were accurately measured, but I doubt very much that they measured this at 10 since the standard turbidity test normally stops at 30 (some go to 20). If your pool store used a colorimeter, then they could have measured the 10, but there have been reports on this forum of some pool stores reporting 100 minus the actual measurement (which would mean 90 in your case) so I'm concerned we don't really know what the true CYA level is. If you can get a test kit to measure this yourself, that would be best (I'm assuming you didn't do the CYA measurement yourself since the test kit doesn't show 10).

Anyway, if you can let us know if 10 is the real CYA level then that would be helpful for determining the next step after you get your TA lowered. If your CYA is truly that low, then you can continue to use Tri-Chlor tablets in your automatic chlorinator for a while (you'll still need to add base, such as Borax, periodically since Tri-Chlor is quite acidic) until your CYA gets up to a higher level, probably at least 30. The actual level you should have is somewhat dependent on how much sunlight and chlorine loss you get each day, but generally the proper CYA will be in the range of 30-50 (I keep my CYA closer to 15, but I have an opaque pool cover and very low chlorine loss levels).

After your CYA is at the proper level, you should stop using the Tri-Chlor tablets and switch to a liquid chlorine (sodium hypochlorite) source -- either chlorinating liquid which is concentrated chlorine or liquid bleach (Clorox Regular unscented or Clorox Ultra again unscented). You will not need to adjust your pH as much after switching to a liquid chlorine source.

Hope this information helps.

Richard