Test results on new pool in Tucson

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Originally Posted by PoolDoc

If you have a concrete pool, lowering the carbonate alkalinity may not be something you want to do. Aeration raises pH by lowering acid carbonates (carbonic acid and dissolved carbon dioxide). This in turn results in reduced alkalinity (bicarbonates and carbonates).

Also, the note about the bleach products was just a caution -- I really had no idea whether it had been an issue for you.

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I'll chime in on aeration by saying that I leave my spa spillway running along with the pool (one return to the spa and three returns to the pool, 50/50 split on the three-way valve) and I run my waterfall 2X per day for 45 mins at a time to make sure the basins in the waterfall always "see" chlorinated water everyday. With all that, my pH sits happily at 7.7 and rises every 3-4 days while my TA is solidly 70ppm. I don't like to drop my pH much below 7.6 or else my CSI get s a bit too negative for my comfort and my alkalinity drops.

If rising pH is a problem for the OP, I would suggest adding 50ppm borates to the water to help control pH. I did back in August and my acid additions went from every other day to once or twice a week. Before borates, my pH liked to sit at 7.6 (seemed to hover there and then rise) but now it likes to "settle" on 7.7 for a few days before rising.

Please Note - Adding borates DOES NOT REDUCE the total amount of acid needed to reach a certain pH level. It only lengthens the intervals between acid additions. SO you will still be adding as much acid as before, just not as often.

Thanks all, and hello fellow tucsonian. I wish I had a spa spillway, I just have a 4x6" overflow vent from the spa to the pool, which I overaccounted for initially, and ignored the potential variation in the water chemistry balance difference that could occur between the two.
The water feature is just an independent 2 spouts that bleed off the pump, so running them lowers the efficiency, but it looks pretty.
I'll think about the borates and follow the trend for now. Good info on the aeration effect, thanks.
I definitely see how the cooler nights are reducing cl demand. Between the August heat and the probable algae bloom that was living under my radar, the bleach use was insane. Kids swimsuits faded noticeably.

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Originally Posted by Wilco

Thanks all, and hello fellow tucsonian. I wish I had a spa spillway, I just have a 4x6" overflow vent from the spa to the pool, which I overaccounted for initially, and ignored the potential variation in the water chemistry balance difference that could occur between the two.
The water feature is just an independent 2 spouts that bleed off the pump, so running them lowers the efficiency, but it looks pretty.
I'll think about the borates and follow the trend for now. Good info on the aeration effect, thanks.
I definitely see how the cooler nights are reducing cl demand. Between the August heat and the probable algae bloom that was living under my radar, the bleach use was insane. Kids swimsuits faded noticeably.

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Yup, I'm over on the east side of town.

Just completed my first full year with the pool. I had a nascent algae bloom S-) back in May that almost exploded on me but I caught it in time. Having learned about the BBB method before the full summer heat kicked in is what saved me. I had to dump ~ 30% of my water due to a high CYA level (150ppm) but as soon as I did that and cleaned out all the algae with a 3-day SHaPE process (Shock, Hold and Patiently Evaluate....I like silly acronyms!), my pool water was clear all summer long while my neighbors fought algae blooms left and right.

Adding the borates is definitely an optional procedure to consider. Honestly, I waited because I wanted to understand the "life-cycle" of my pool water better before adding another variable to the mix. It's surprisingly easy to do (I used boric acid instead of the Borax/Muriatic Acid method) but there are few conditions you have to follow to get it right.

Enjoy the pool!!

My cya is 100-110, previous owners probably relied on tricolor pucks it would seem. Was going to see if it went down over winter. I have a pebble tec pool with multicolored tiles on rim. Horrible scaling build up. I have used pumice ( go through it way too fast), de scaler spray ( not a chance) paint scraper ( lots of forearm fAtigue) and recently a chisel and hammer ( use correct angle to avoid tile chipping). Really looks like hell. Any thoughts?

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Originally Posted by Wilco

My cya is 100-110, previous owners probably relied on tricolor pucks it would seem. Was going to see if it went down over winter. I have a pebble tec pool with multicolored tiles on rim. Horrible scaling build up. I have used pumice ( go through it way too fast), de scaler spray ( not a chance) paint scraper ( lots of forearm fAtigue) and recently a chisel and hammer ( use correct angle to avoid tile chipping). Really looks like hell. Any thoughts?

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Your CYA is only going to "naturally" decrease VERY slowly, ~2-3ppm/month at best during the winter. My suggestion, if you want to reach a lower level faster, is to drain and refill. Taking you water level down by 25-30% would put you in a much more manageable range. Just my opinion, as others feel 100ppm is OK to run at since you'll just use more bleach that way.

As for scale, Arizona Bead Blasters (http://www.arizonabeadblasting.com/) used to service Tucson. I'm not sure if they do anymore. Salt blasting calcium deposits is the better way to go. If the process is tuned right, you blow away all the Ca scale without any damage to tile or PebbleTec. It costs money, but unless you have your own salt blasting equipment, it might be worth saving you arms the trouble. Pumice stone will definitely scratch your tile surface and won't help at all on the PebbleTec or rock surfaces. Diluted muriatic acid can help a bit but you'd better wear gloves and face gear to protect yourself.

Looks like they will come to Tucson for $75 fee. Very nice guy contacted me back. Thanks, might tie it in with draining the pool a bit which they need to do anyway.

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Originally Posted by SunnyOptimism

Your CYA is only going to "naturally" decrease VERY slowly, ~2-3ppm/month at best during the winter.

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This statement is not necessarily true. Some pools lose all of their CYA over the winter. We see it all the time. When this happens (CYA biodegrades), you are often left with ammonia in the water as a byproduct and a huge chlorine demand upon opening. No way to tell which pools this will happen to, unfortunately.

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Originally Posted by Wilco

Looks like they will come to Tucson for $75 fee. Very nice guy contacted me back. Thanks, might tie it in with draining the pool a bit which they need to do anyway.

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Cool. Let me know how it goes, I was thinking about buying my own salt blasting equipment to do the job but if they do good work for you, that would be good to know. My scaling isn't too bad but I wanted to do the job over the winter.

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Originally Posted by Watermom

This statement is not necessarily true. Some pools lose all of their CYA over the winter. We see it all the time. When this happens (CYA biodegrades), you are often left with ammonia in the water as a byproduct and a huge chlorine demand upon opening. No way to tell which pools this will happen to, unfortunately.

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Thanks @Watermom! I was going to add that into my statement but did not want to get into the weeds about it. I think the CYA-Ammonia conversion only happens in pools that are "closed" over winter. In those pools, the low-level algae that forms (after all the chlorine and polyquat is gone) then converts the CYA into ammonia. I have not heard of that happening in a pool that is run all year round like we do here in the Southwest because, presumably, we hope to have no algae in our pools to do the conversion but I would be interested in hearing about cases where CYA was consumed by some other chemical mechanism. I guess if a pool was allowed to turn into a green swamp, then the algae would consume all the CYA and produce ammonia, but that would be the extreme case of someone just neglecting their pool.....Hey! Maybe that's the solution to excessive CYA!?!?! Let your pool turn into a swamp for a while until your CYA levels go to normal :p

joking!!

Guy quoted me $300 to do the salt blasting. He's coming Saturday, will let you know how it goes.

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Originally Posted by Wilco

Guy quoted me $300 to do the salt blasting. He's coming Saturday, will let you know how it goes.

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AWESOME!! :):)

So $375 with the travel fee. Not bad. I priced out a 100lb sand blasting tank and 130psi/6gal air compressor at a little over $400. Add in 100 lbs of the kieserite material they use (basically hydrated magnesium sulfate salt) and you easily go over $500 for a DIY setup. Not to mention you need a modified shopvac or pressure-side cleaner with a fine mesh bag to vacuum up all the calcium scale and spent salt at the bottom of your pool...you'd have to do two or three DIY jobs before the equipment starting paying for itself.

If you can, please post before and after photos (especially of the worst areas) so we can all see the results. Ca scaling is a huge problem out here in the Southwest with our plaster pools and hard water, so I'm pretty sure others will be interested. Probably a good idea to start a new post so others will see it.

In case you're interested in reading about the soda blasting process, this site has good technical info -- http://www.universalminerals.com/maxxclean.shtml