New Pool - Multiple Issues

[JimR]

Hi All,

New pool owner that stumbled across this site. Thanks to all for the info I have found so far. Hope you can help me with some of these issues.

First, we have a new 20' x 40' rectangular inground with a vinyl liner and diving well in Richmond, VA. We just filled our pool beginning Wednesday and finished filling Thursday. I noticed a slight green tint to the pool Thursday evening and it was murky green in the deep end by Friday evening.

One complicating factor is we purchased a 2 speed Hayward pump that is only working on low speed. Tried to connect power directly to L-1 and L-2 on the pump and it is low speed on both. Pool builder can't switch out until Monday.

Took a sample to the pool store and they gave me the following results:

FC = 2

TC = 2

PH = 7.6

TA = 9.0

CH = 80

CYA = 0

TDS = 300

Phos = 1,000

In reading quickly on the site, I know the CYA is low, but that helped with the shock level last night. I added 4 182 oz bottles of 6% bleach to bring the FC up to 10. I also added a couple of 3" tabs to the skimmers and brushed the pool.

I went to test the level this am with the $5 kit I picked up at WalMart only to find it tests to 5 ppm. I will order a Taylor this afternoon.

I guess my questions are:

1. Any suggestions on getting the pump to high speed?

2. Should I add CYA to bring it up?

3. Will the chems work with the pump on low?

4. Should I keep the chlorine up at 10 ppm?

5. Can we swim at that level?

Thanks in advance for any help.

Jim

[JimR]

Also forgot to mention, we have a SWG that we haven't started yet. Starting up this afternoon (wait 24hrs after putting salt in the pool).

Thanks,

Jim

[PaulR]

With zero CYA, most of your chlorine will be lost to sunlight before it can kill off the algae. You want 20-30ppm CYA in there right away. You didn't say how many gallons of water are in the pool, but 2.5lb granular CYA (100%) per 10,000 gallons will get you to 30ppm.

Shooting for FC 10 with CYA 30 is a good shock level. Stick with that until the algae has cleared up. It's okay to get the SWG started at this point but it probably won't be able to keep your FC at shock level by itself; you'll need to supplement with bleach.

After the algae is gone, put in another dose of CYA and shoot for 60ppm. At that point you can start fine-tuning your SWG to maintain an appropriate FC level.

Regarding the pump, low speed is normally fine, a lot of people just leave it on low 24/7. The dead algae will clear faster if you can run it on high, though, and of course you want a pump that actually works properly.

--paulr

[waterbear]

First, PaulR gave you sound advice, follow it. Once the algae is gone and you are maintaining a FC level you can try these tips:

Most SWG manufacturers recommend a CYA of 80 or 100 ppm. It is important to have this level because it translates into better pH control in the long run. I won't bore you with the chemistry now but I have documented it many times on this and other forums, however rising pH because of outgassing of CO2 is one of the main downsides to SWGs

With a SWG keep your TA at 60-80 ppm (your 90 ppm is livable but do not add any baking soda or soda ash!) and keep the pH at 7.6 and not lower. This will also translate into better pH stability.

Once you get the CYA up keep your FC at 4-5 ppm and you will be good.

What make and model SWG do you have? I can give you more tips if I know which you have.

Pool will circulate fine on low speed, just need to run it longer. Running for 12 hours on low speed is actually more energy efficient than 6 hours at high speed, which is why people use 2 speed pumps.

With no CYA 10 ppm FC is a bit high but it is not with even as low as 29-39 ppm, yet if you wear an old bathing suit you can swim. Bathing suit might get bleached a bit.

[JimR]

Thanks PaulR and Waterbear!

The pool size is 36,000 gallons. The salt generator is an Aqua Rite with a T-15 cell.

I have been out of pocket but have accomplished the following since your reply:

Pump is fixed and makes a big difference on high.

Salt generator is running and we have added a 3 bags of salt. Currently at 2,700 and climbing.

I picked up a TF-100 test kit and got the first results last night of:

FC - 5

CC - 0

TC - 5

PH - 7.4

TA - 120

CYA - 28 ish

The algae appears to be gone but the water isn't crystal clear...may be the salt we put in yesterday. I added CYA granuals last weekend to get to the 28 and put them into the skimmers. Was told they would dissolve in the filter, just don't back wash. I have a half a bucket that I can still put in.

I also have 4 chlorine tabs that I believe add CYA?

I guess I have a couple of questions. What should I do for the high TA. Any adjustments on other chems and what is a good strategy for running the 2 speed pump or should I just keep it on low unless needed on high for vacuuming or mixing in chemicals?

Any advice to move forward would be appreciated.

Thanks,

JimR

[waterbear]

Thanks PaulR and Waterbear!

The pool size is 36,000 gallons. The salt generator is an Aqua Rite with a T-15 cell.

I have been out of pocket but have accomplished the following since your reply:

Pump is fixed and makes a big difference on high.

Salt generator is running and we have added a 3 bags of salt. Currently at 2,700 and climbing.

You want the salt at 3200 ppm.

I picked up a TF-100 test kit and got the first results last night of:

FC - 5

CC - 0

TC - 5

PH - 7.4

TA - 120

You need to lower this to around 70 ppm. too bad you got a TF100 and not the Taylor K-2006 since the acid demand test is very helpful when lowerint TA and the 2000 series pH comparators are much more precise than the 1000 series comparator you have in the TF100.

To lower TA is a process:

1)You add acid to drop the pH to 7.0 and not lower with a vinyl pool. The act of adding the acid and dropping the pH is what lowers the TA.

2) Test the TA (at first it will not move much, if any but don't give up)

3) Aerate the water to drive off CO2 and raise the pH without affecting the TA (I won't go into the chemistry behind it now but this is what is happening and why you can't use a chemical like soda asch or borax to raise the pH here)

Aerate meant to 'shake up' the water any way you can like a pool party of splashing children, a fountain attached to a return, a compressor bubbling air into the water like an airstone in an aquarium, etc. The better you aerate the faster the pH will rise. If you do nothing it will also rise but much more slowly.

4) when the pH rises above 7.4 lower it again to 7.0 and repeat from step 2 until the TA is where you want it.

CYA - 28 ish

You want this at 80 ppm! You will need 3lbs more to raise this to about 80 ppm in a pool your size.

The algae appears to be gone but the water isn't crystal clear...may be the salt we put in yesterday. I added CYA granuals last weekend to get to the 28 and put them into the skimmers. Was told they would dissolve in the filter, just don't back wash. I have a half a bucket that I can still put in.

I also have 4 chlorine tabs that I believe add CYA?

Very little, for each 10 ppm FC added by a tab you will add 6 ppm CYA. In a pool your size that translates into one 6 oz. tab adding about 1.1 ppm FC and about .7 ppm CYA or an 8 oz stick adding about 1.5 ppm FC and .9 ppm CYA.

I guess I have a couple of questions. What should I do for the high TA.

Lower it as I indicated.

Any adjustments on other chems and what is a good strategy for running the 2 speed pump or should I just keep it on low unless needed on high for vacuuming or mixing in chemicals?

It's what most people do. If your normal run time on high is 8 hours then give it 16 hours on low You will probably have to adjust the output on the chlorine generator to maintain your FC level where you want it. I would suggest 4-5 ppm FC.

Any advice to move forward would be appreciated.

Thanks,

JimR