Please help this newbie pool guy

[mcconns]

Hello everyone,

Just found this board and have been cruising and surfing all the interesting info. I just want to say that now I am really confused. I am very new to pool upkeep, my first time. I am helping out with a community pool in the state of GA. Our state requires frequent county inspections, and I am afraid I will not pass the next inspection. Here are the current specs;

Pool size: 90,000 gals
Type: Concrete
Pumps: twin 3hp (24/7)
Filters: twin triton II 140’s (24/7)
Flow: ~320 GPM

Chlorination: Auto (Trichlor 3” pucks)
Drains: (2) Bottom
Skimmers: 6
Returns: (10) bottom
Depth: 3.5 / 5.0 / 4.0 (ft)

TC: 3.0
TA: 110
pH: less than 7.0
CH: 400
CYA: 100

TA was greater than 300, chlorine was 7.0, and pH was 7.8

I have added 31 gal of Muriatic acid to get the TA to 110. Now to get the pH up I have added 61 lbs of 20 Mule Team Borax, and 50 lbs of Soda Ash. The TA and/or pH is not moving!! What am I doing wrong?

I apologize if this has been done before.

Thanks
Mac in GA

 

[sevver]

You should read this topic: HERE

The only way to lower the TA permanently is through Aeration. Having such a big pool, you could drop a couple of sump pumps in there, with hardpipe to the surface, rigged up somehow to a couple of fire hose nozzles, or something to that effect. I am sure that the fire department would let you borrow them temporarily. You could run them at night while the pool is closed.

 

[chem geek]

The fastest and most effective form of aeration that has been found (so far) is to use an air compressor with a nozzle that produces tiny bubbles when the nozzle hose end is put into the deep end of the pool. Of course, any additional aeration from other sources would be helpful, but having the air bubbles be very small helps since it's more surface area per volume of bubble. Aeration will raise the pH with no change in TA -- which is exactly what you want right now.

 

[mcconns]

How about a 20 ft length of 1" PVC drilled with many small holes weighted down to stay on the bottom and the air hose connected to it operating at about 20psi.

To elaborate?

Do I need more pressure?

I don't want to burn up a compressor running it overnight

Thanks
Mac in GA

 

[chem geek]

Your pipe sounds like a good idea. I don't know enough about air compressors to know what to do to prevent them overheating (i.e. how long they can run, etc.). Maybe others know. You should try running it for an hour and remeasure pH before letting it run overnight. You will be amazed at how quickly it works and won't want to go "too far" in raising your pH (the pH will rise more slowly at first and then will rise more quickly as the pH gets higher). Of course, it's easy to lower it and add more TA as needed if you do "overshoot".