Falling Alk in a SWG Pool

[texasbrew]

I am having problems with constantly falling ALK in my pool. I am using a SWG. I am adding acid almost daily at a rate of 16 to 20 ozs per the Pool Calc for the Iphone. I am only dropping my PH to 7.4 from whatever the reading is that day for the PH and ALK. I am currently sitting at 70 and I will probably add 2 lbs of baking soda before I leave town to get the ALK up to 80. Does anybody have any ideas as to what may be causing the ALK to drop? I have a bubbler on the sunshelf but I thought that would only come into play if the PH dropped to around 6.8. My CH is 550.




Thanks-

 

[svenpup]

How high do you let the pH get before you add acid?

You could let the TA drop to around 60, and let your pH get up to 7.8 and see how long it takes to get 8.0. Then try to keep it around 7.8 instead of constantly trying to get it down to 7.4

The problem is that SWCG along with high TA is going to make you pH rise. If you try to overly constrain pH, TA drops along with it. Then you bump up the TA and the issue continues. I have seen several of the Mods here say that they keep their TA at 60 and their pH levels off at 7.7 - 7.8

 

[Bama Rambler]

Does it stabilize at 70 or does it drop down any lower? I wouldn't keep fighting it if it does.
Also a lot of pools like the pH to be 7.8. If you leave it alone once it gets to 7.8 does it keep rising? If it doesn't then that may be your sweet spot.

 

[texasbrew]

I try to keep the PH between 7.6 and 7.4 because of the CH being at 550. It does seem to sneak up on 7.8 on occasion. I will let the TA fall to wherever it wants to go I suppose but I was concerned that it might want to keep going much lower than 60.


Thanks-

 

[texasbrew]

If I don't stay on top of the acid it will go off of the scale on the PH (I am using the TFTestkit).

Thanks-

 

[JasonLion]

The PH is going up because TA is too high. You can let the TA come down to 60 and that will help a fair bit. To get the PH to stabilize as low as 7.6, you may need to lower the TA below 60. You should only let TA go below 60 if you have borates in the water. The borates will help stabilize the PH so that a lower TA level (down to 40) is alright.