The Great Tetraborate Experiment!

[mbar]

I have used the chemistry store to buy ascorbic acid - they are very dependable, and will even answer any questions you have. The chemicals are delivered quickly too.

[mbar]

Have you tried Lowes? I know they sell it, so you can order it online from them.

[sailork]

I get mine at Home Despot. I think there are some shipping restrictions on the stuff so it might not be so simple to order.

Oh, and I'm pretty sure that swimming pools are the most common usage so look on the "pool aisle."

[waterbear]

Ace Hardware also usually carries it...and you can get it in just about any pool store. In my area one of the pool stores (NOT the one I work at) has the best price I have been able to find....so don't rule out the pool stores, it is possible to shop in one without getting "poolstored"!

[waterbear]

Week 5 and some strange test results! I have not done anything to the pool after last weeks tests except vacumn and put a new cart in the filter so I could soak the old one (It's been in a year and was looking a bit grey...after soaking in Electrosal automatic dishwasher detergent overnight and hosing it off it now looks brand new!)
We did have a few days with no sun and a lot of rain because of Ernesto. The water in the pool is a bit higher than usual but not as high as last week. It's been sunny and hot the past 2 days so there has been some evaporation.

Borates still about 50 ppm....the test strips have division for 30, 50, and 80 and it is between 30 and 50 and much closer to 50 than any other color. I would have to say around 45 ppm. Still within the "good" range and will probably go up when the excess water evaporates.
FC 10 ppm ppm Don't understand this at all....might be from the days with no sun but I just can't explain this!(I lowered my SWG output last week after the test and my FC went UP!)
CC 0 ppm
TC (oto) l10 ppm also, Shotglass method 1:1 dilution
pH 7.6 (rechecked this, Used both Ben's kit and Taylor 2005...it's still holding....5 weeks and I have not put any acid into the pool! don't know if the rains kept the pH down or what)
TA 100 ppm ( was 90 last week, accuracy of the test is 10 ppm so this is basically the same. rains seem to have had no effect on TA!)
Adjusted alk 78 ppm (CYA up to 65 ppm since water in pool is not as high as last weeks test. was 60 ppm last week)
Calcium 180-190 ppm (did test twice, was 170 last week because of dilution from rain, water level in pool a bit lower now)
CYA 65 ppm (up a bit from last week because of water level in pool lower from evaporation)
Salt 3200 ppm (readout on AquaLogic) (temp of water is a few degrees lower than last week and Aqualogic is not temp corrected when it calculates salt level so this makes sense. Guess I should be including the temp readings also...this week 85 degrees, last week 88 degrees.
Salt 3200 ppm (Tayor K-1766)precison of test is 200 ppm so this is essentially the same as last weeks test of 3400 ppm
Pool is still clear and sparkling.
Didn't test the spa this week....got dark before I could get to it. If I get a chance to test it on sunday I will post the results.
The only thing I can't explain is the high FC levels! I have done nothing to the pool except vacumn and put in a new cart last Saturday! Haven't used the pool or spa all week. Perhaps that is part of it and the water is a bit cooler. gonna wait another week and see what happens. Cell in on 6% with an 8 hour run time....might knock a few hours off the run time in a week and see what happens if the FC stays up around 10 ppm.

Can't believe that I have not put acid in the pool in 5 weeks! I still think the rains are what has kept the pH down but during rainy season last year the pool still needed acid every 2-3 weeks! I did have to cut my pump run time down last october to 6 hours a day because it was not so warm and my FC was high....cell output was on 6% then also. This might be what is happening now.

[chem geek]

FC 10 ppm ppm Don't understand this at all....might be from the days with no sun but I just can't explain this!(I lowered my SWG output last week after the test and my FC went UP!)

The largest process of chlorine consumption is the breakdown from sunlight where up to around half of the FC can be consumed each day of full sun. So let's say for sake of argument that you were maintaining 4 ppm FC (your previous reading) and that normally sunlight would consume about 2 ppm of this each day so let's say that your cell was producing 2.5 ppm of chlorine -- 2 ppm for replacing the chlorine broken down from sunlight and 0.5 ppm for oxidation of organics and killing of bugs and preventing algae. If there was little or no sunlight (UV), then if you were in a steady-state of chlorine before, then now you would build up 2 ppm of extra chlorine per day. That's my best guess as to what happened here. Once sunlight returns, the high chlorine levels will get cut down quickly since the same "half-life" rule will apply (so you might go from 10 to 5 or 6 FC in one sunny day).

It's great news that your addition of acid has dropped to virtually nothing, but the borates should only be affecting the buffering of pH and not the actual use of acid itself, except for the reduction in chlorine consumption (and therefore SWCG output, including aeration from hydrogen gas) due to the borates taking over some of the role of preventing algae. So when the time comes when the pH does rise, it will take a lot more acid to move the pH a small amount so that the net amount of acid you have to add might be close to what you used to do per unit time (again, except for the reduction in chlorine production) -- it'll just need to be added less frequently. We'll see if this is true or not...

Of course, you reported in another thread that you found a pH rise even with a solar cover. So we still haven't really figured out the true source of your pH rise yet. I'm still guessing that at least some of it might be chlorine outgassing (perhaps this gets through or around the solar cover or the hydrogen gas bubble aeration still works???) in which case your current lower SWCG chlorine production levels due to the borates taking over some of chlorine's prevention of algae growth will also lower chlorine outgassing due to aeration from hydrogen gas bubbles. As of now, your pH rise is still a mystery to be solved (hopefully).

Richard

[waterbear]

Week 6....numbers haven't changed much at all! Last Saturday I adjusted the actuator on the return so when in pool mode water flows into the spa at a very slow rate yet the pool returns still have basically full force. The spillover just trickles. This makes the pool and spa one slightly larger body of water (about 6850 gal). I wanted to see what impact this would have...aeration from the spillover in pool mode is minimal. I lowered the spa only run time to 30 minuets/day and kept the cell output at 4%
Pool cell output has been at 5% since last Friday. I did this so I would not have to treat the pool and spa as separate bodies of water but I also did not want the spillover running all the time since it turns off the pool returns.

Tested the water after the pump had shut off in spa mode so I could see if there was a difference in FC readings. There was. Spa was 1.5 ppm higher which is just what I want! (However pool is still a bit high, lowered cell output in pool mode to 4% and will see what happens in a week.) I did a quick check of chlorine levels in spa and pool on Tuesday while in pool mode and both were 8.5 ppm.

Here are the numbers:
Pool FC 7 ppm (Lowered output on cell to 4%today after test, pump run time still 8 hours total)
CC 0 ppm
Spa FC tested after spa only mode 8.5 ppm Spa only mode runs 1/2 hour a day with cell output on 4%
CC 0 ppm
(If I can get the pool FC down and still maintain about a 1.5 ppm higher level in the spa I will be very happy)

pH 7.6-7.7 ( both Ben's kit and Taylor 2005, If pressed I would have to say it's closer to 7.7...it's still holding....decided to put in some acid to drop it down to about 7.5, calculated that I would need about 6 oz.! That's 6 oz. of acid total in 6 weeks! Before the borates I was putting in 24 oz. every 3 weeks!)
TA 100 ppm (Still holding)
After adding the acid the pH was right on the money at 7.5 by Ben's kit and looked to be between the 7.4 and 7.6 on the Taylor kit. I retested the TA twice and still got 100 ppm. I guess 3/4 cup of acid is not enough to affect the TA to any great degree in my pool.
Adjusted alk 76 ppm (CYA back up to 70 ppm since water in pool is at normal level)
Calcium 190 ppm (still holding)
CYA 70 ppm (water level in pool back to normal)
Salt 3100 ppm (readout on AquaLogic) (temp of water is 83 degrees...cooler than last weeks test)
Salt 3300 ppm (Taylor K-1766, got a slight persistant red color at 16 drops, 3200 ppm, but it was not as dark as normal, full color reached at 17 drops, 3400 ppm, so I figure it's about 3300 ppm...normal range anyway)
Pool is still clear and sparkling.

I am not going to post any more in this thread unless there seems to be some major upset in the numbers or my acid use. I am satisfied that the addition of borates to the water DOES do the things claimed for it! I would recommend this to anyone that might want to try it! The most surprising one is the reduction in chlorine demand in my pool. Would love to find out why that is occurring but am not complaining! I was thinking that the lower water temp might be the cause but I have checked the temp during the day and it's still been 88 degrees. It is cooling off more at night though. Perhaps this is the reason. Pool heater has been off through all these test results. Only the spa is heated when in use or when the pump runs in spa only mode.

Perhaps this is tied in with the lower chlorine demand because of the algaestatic properties. I am thinking that if algae doesn't start to grow then less chlorine is used. Perhaps algae is always trying to grow in a pool and the chlorine is killing it and the stuff I was vacumning and collecting in the skimmer sock was dead algae. I have to vacumn less now and my skimmer socks don't need to be changed weekly. They are good for about 2 weeks now. Would appreciate any feedback on this theory.

[chem geek]

This is great news Evan. The Borates look like they have had nothing but positive results.

I calculate that 6 oz. of Muriatic Acid in 6850 gallons with your other numbers would lower the pH from 7.7 to 7.60 (or 7.6 to 7.49) due to the 50 ppm of Borates that help buffer the pH. With no Borates, you would go from 7.7 to 7.47 or from 7.6 to 7.40 so I'm not sure what's going on with what you saw. It could be in the ballpark for the 0.1 drop, but it seemed like you saw something closer to 0.2

An earlier post of mine in this thread showed this link that indicates Boric Acid does kill algae or inhibit algae growth so I believe your theory may be correct. The Boric Acid is killing nascent algae so that chlorine does not have to and this results in a lower consumption of chlorine, but I wouldn't expect this to be that much lower. As I mentioned in a previous post, most chlorine consumption is from breakdown from sunlight so if you see a large reduction in chlorine consumption then somehow Boric Acid is shielding the chlorine from sunlight. I doubt that is happening so perhaps other factors are coming into play as the season cools down, as you said.

As for the lower acid demand, that is the actual amount of acid added over time as opposed to the amount the pH rises, it is possible that this is related to the lower chlorine consumption because you had to lower your chlorine generation output level to about half of where you were before. If things were linear, then this would have cut down CO2 outgassing in half and cut the acid demand in half, but things are probably not linear when it comes to aeration so I'm betting that you would have still had a high acid demand if you had kept your chlorine output the same (but your FC would have been too high so that was not an option, even for an experiment).

Anyway, the bottom line is that Boric Acid has significantly helped your situation of rising pH, has cut down your chlorine consumption, and feels good (makes the water sparkle). Thanks again for turning us on to this product.

Richard

[waterbear]

I calculate that 6 oz. of Muriatic Acid in 6850 gallons with your other numbers would lower the pH from 7.7 to 7.60 (or 7.6 to 7.49) due to the 50 ppm of Borates that help buffer the pH. With no Borates, you would go from 7.7 to 7.47 or from 7.6 to 7.40 so I'm not sure what's going on with what you saw. It could be in the ballpark for the 0.1 drop, but it seemed like you saw something closer to 0.2

Richard

Richard,
Like I said the pH was 7.6-7.7 as best as I could tell before I added the acid. After it was sitting right at 7.5 so I guess it was closer to 7.6 than 7.7 -- a .1 change in pH is probably about right.

It is definitely in the ball park!
So, my question to you is....When are YOU putting borates in YOUR pool?

[chem geek]

So, my question to you is....When are YOU putting borates in YOUR pool?

Since the pool is used by both my wife and I and she uses it during the week when I don't, she has the final say in this. I've talked to her about adding salt (to around 1000 ppm) for a silkier feel and about adding Borates as well and she's game. So now the ball is in my court so I just need to get my lazy butt off the couch and do it!