hottubbinandy

Done: pH: 7.5 TA: 70

Addition #7 pH: 7.8 TA: 90 Add: 2.1 oz Total: 24.6 oz dry added so far...I am over the ~24 oz total from start, but I have been dissolving the dry in new tap water (since I have had alot of evap over past two days trying to figure this stuff out)

Addition #6 pH: 7.8 TA: 110 Add: 2.6 oz Total: 22.5 oz dry added so far

Addition #5 pH: 7.8 TA: 120 Add: 2.8 oz It appears I am making progress

I have read Nitro's Maintenance post and the Lowering TA posts, trying to make sure I am doing this correctly. First time hot tub owner, with zero prior knowledge of water chemistry Sorry for the long post, but hopefully one of you guru's is willing to read thru this My starting numbers, from the city water tap: CH: ~240 (only have test strips) TA: 260 PH: 8.0 Tub size: 440 gallons Tub temp: 104 Ideal TA: 72 (according to pool calculator) What I have done (read that as my interpretation of the above posts): To start dropping the TA, I punch in above with target of 7.0 pH, and it says to add 5.5 oz by weight dry acid. Dissolved the above dry acid in bucket and added and let mix with jets and circular for 30 minutes. Repeat. Here is my results: Addition #1 pH: 8.0 TA: 240 Add: 5.5 oz Addition #2 pH: 7.8 TA: 210 Add: 4.6 oz Note: yellow'ish line on the tub an inch or so above water line and a whitish scale on the water line around the tub now. Rubs off fairly easily towel. Addition #3 pH: 7.8 TA: 160 Add: 3.6 oz Addition #4 pH: 7.8 TA: 150 Add: 3.4 oz Total (dry acid so far 17 oz) Now my questions... The yellow'ish line...should I be concerned? E.g. did I add too much dry acid at once? This sure seems like alot of dry acid. From the taylor box, it estimates 3.4 oz dry per 1000 gallons to drop 10 ppm TA. For my tub, I need 160 ppm drop in TA, so that is ~23.936 oz of dry acid to be added. Do I just keep chipping away like I am doing?