Coexisting LC and Trichlor

gounseen

Member
Mar 19, 2025
5
DFW, Texas
Pool Size
15000
Surface
Plaster
New pool owner and recent joiner here. We purchased a home with a pool 6 weeks ago and I think I’ve managed to keep things well enough in order. Here are today’s levels and the pool details:

TA: 100
pH: 8.0
FC: 5.4
CC: 0.0
CYA: 30-40
CH: 300
Temp: 78

15k gal concrete pool with PebbleTec finish. VS pump running at 2200 rpm for 8 hours per day, plus 1 hour at 2500 rpm for the robot.


A few things I’ve noticed:

- My pH likes to climb. We’ve had a lot of rain lately which is affecting my levels, but I also think our water features (waterfall & fountain in the spa) are contributing to these quick pH climbs. Any suggestions for stabilizing things or is this pretty normal? I’m adding acid weekly to bring it from the 8.0 range to 7.4.

- Are there any issues with using both Trichlor pucks and liquid chlorine as sanitizers? I have a 25 lb bucket of Trichlor left over from the prior owner and I’d rather not waste it. I’ve also purchased some 10% LC per the TFP quorum’s recommendations. Since my CYA isn’t high, I’d think I can sanitize using a combined approach until I run out of Trichlor or my CYA climbs too much. Any concerns with this approach?

- I get some calcium scale on my tiles, but my CH is well within range. Is this a function of high pH? We do have hard water here in TX, but CH is in range despite the scale appearing.

All things considered though, it’s been an enjoyable experience so far. The prior owner left the pool in great condition. This, plus buying a Taylor K-2006 have made things pretty simple for far.

Cheers
 
- My pH likes to climb. We’ve had a lot of rain lately which is affecting my levels, but I also think our water features (waterfall & fountain in the spa) are contributing to these quick pH climbs. Any suggestions for stabilizing things or is this pretty normal? I’m adding acid weekly to bring it from the 8.0 range to 7.4.

Your TA of 100 plus the aeration from your water features are causing your pH to climb.

Let your TA drop to 50-60, and the pH rise should slow down.

Consider limiting the running of your water features.

Do you have automation?

- Are there any issues with using both Trichlor pucks and liquid chlorine as sanitizers?

No.

I have a 25 lb bucket of Trichlor left over from the prior owner and I’d rather not waste it. I’ve also purchased some 10% LC per the TFP quorum’s recommendations. Since my CYA isn’t high, I’d think I can sanitize using a combined approach until I run out of Trichlor or my CYA climbs too much. Any concerns with this approach?

Where are you putting the Trichlor tablets?

Do you have a gas heater?

- I get some calcium scale on my tiles, but my CH is well within range. Is this a function of high pH? We do have hard water here in TX, but CH is in range despite the scale appearing.
 
Thanks for the reply. No automation - I could shut off the waterfall manually for a while though.

I have two deck boxes on the side of the house. One for chlorine products and one for acid. The Trichlor is separate from the LC and stored on the same level, but they are in the same box. The box is not airtight so offgassing can still occur.

The heater is gas.
 
Where do you put the tablets in the pool? An inline chlorinator, the skimmer basket, or a floater?

Trichlor tablets in an inline chlorinator will murder a gas heater.