salt water pool in AZ

[steveinaz]

I can confirm for you, as I'm awaiting my new pentair SWCG to arrive, and having to do the 'ol BBB method for a couple weeks---THAT I MISS MY SWCG! What pain in the rear adding bleach everyday. VIVA SWCG!

Here is another factor we sometimes forget---you can always "back out" of a SWCG if you find it's not your cup of tea (can't imagine that happening). You'd simply remove the cell, have straight PVC popped in place, and go back to traditional chlorination.

[PoolDoc]

If your CYA is in the 50-80ppm range recommended by Pentair, and you dose according to the Best Guess Chart, you should be able to go every other day. If it's below that, you might want to buy some dichlor. On your pool (13K gallons), each pound of dichlor will add about 5 ppm of chlorine, and about 4.5 ppm of CYA. So, if your CYA is 40 ppm, and you need to get it up to 80, since it will drop slowly once the SWCG is back on, you can use about 30# of dichlor.

If you have a Sams Club nearby, they sell PoolBrand dichlor for ~2.20/lb for 50#, and ~3.00 for 12# bagged shock. Otherwise, you can get Kem-Tek dichlor for ~4.00/lb from Amazon, shipped free, in whatever size works.

[steveinaz]

Thanks Ben,
I've only done the following testing so far this spring, after the 1/2 drain:

CYA: 70ppm
Salt: 2600ppm (currently) will bump up for pentair this week to 3300ppm
TA: haven't done yet
CH: ran out of reagent! grrrr! Hopefully I'm in the 300's now, CH is a constant burden here.
Ph: 7.5
FC: Keeping it at 2ppm for the time being--water temp is 66 degrees

[PoolDoc]

If you are feeling experimental, you could try lime-softening, which involves pushing the pH up over 10 with soda ash, precipitating the calcium as calcium carbonate, cleaning the System-3 beasts to remove the calcium, and then using muriatic to strip the excess alkalinity. Now that A&H washing soda is available at Walmart, it shouldn't be too expensive.

The Kem-Tek chemical developer says they've been doing this with Intex pool owners, and is willing to help me walk folks through the process. But it's not for beginners, till we've got it down. You'd need to turn off your SWCG and heater (if any) before starting. But, you should be able to take your calcium down to an arbitrarily low value, and remove most any stray metals in the water at the same time.

[steveinaz]

Ben,
When you say "calcium carbonate" is that the snowflake looking stuff?

[PoolDoc]

Calcium carbonate is just limestone or marble dust (used in plaster) -- it's not something you add to your pool. Rather it forms when you have excess carbonate ions (from sodium carbonate or bicarbonate), calcium ions (from calcium chloride flake or beads, calcium hypochlorite . . . or your pool's walls), all at a high-ish pH level.

Probably, you are thinking of calcium chloride. The dihydrate (77% calcium chloride) is a flake; the anhydrous (90+%) is usually beads. The dihydrate (chemically bound water) is far more commonly sold than the anhydrous (no water) material).

[Nomak2]

Was AFK for a couple of weeks. Neat to see the additional info. It's rubber meets the road time, as we are submitting for permits. I have to make a decision on what mfg of equipment we're going to specify. With the info I've seen in the forum, I feel more confident. Thank you.

[aylad]

Good luck with your project--let us know how it's going!!

[Nomak2]

Quick question - was just looking at Doc's review of SWCG on another post...what is the salt range and how important is it? I notice two manufacturers have a very wide range, while the majority have a much tighter range.

[aylad]

I'm not 100% sure of the answer, but I would say that the range is dependent on the unit. Each unit will specify the salt range necessary for it to work correctly. If the salt level is too low, then it won't produce the chlorine you need.
There are SWCG'ers around here that I'm sure will chime in and give you a more definitive answer, though....