Another New Guy with Issues

[KatyTx]

Hi everyone,
I found my way to this site a few weeks ago while searching for info on how to care for the pool that came with our house. This is our first pool experience beyond an inflatable orka whale, so my pool chemistry knowledge level is fairly low. I have read all the basic pool school info now know how little I know about pools! I wish to move to the BBB method, and am interested in adding borates at some point as long as the borates aren't dangerous for the kiddos. I have already purchased 6% bleach, borax, baking soda, and have a borate test kit on order.

In addition to the pool stats in my signature, I have attached some pictures to convey the current situation. As you can see, there is heavy scale buildup on the stone. The bottom of the pool has some dark gray patches that appear to be the result of loss of color in the plaster, but there are some other sandy brown patches that I cannot identify. As you can see in the picture of the spa wall, something has caused considerable pitting. I have had some recurring green algae but I don't see any at the moment. Otherwise, the water is crystal clear.

The lastest test results are as follows:
FC - 6
CC - 0.5
TC - 6.5
pH - 7.8
TA - 140
CH - 450
CYA - 90

Per the Pool School recommendations, some of the readings are out of line. Which is most critical, and is there any preferred order of correction? What is the cause of the patches on the bottom of the pool? Is this algae? From what I have read, the scale buildup is beyond the simple acid wash removal technique so I would need to go with bead blasting or some other method. Has anyone tried power washing?

As a side note, my five-year-old is having a birthday pool party next weekend, whatever I do needs to permit the party to go on as scheduled.

Thanks in advance! Any help is appreciated.

 

[duraleigh]

Hey, Todd,

Welcome to the forum.

First tell me how you have been chlorinating, then we'll start to fix some of your issues.

Also, could you do a quick CH test on your fill water and post that result? Not the pool.....the refill water.

 

[KatyTx]

Dave,
Thanks for the reply. I have been using the 3" tablets and shocking about every two weeks per the pool store instructions.

The fill water CH is at 110. I should have thought to check that.

Todd

 

[PaulR]

Your pH, TA, and CH are all high; this certainly puts you into scaling territory. The best short-term fix is to bring pH down, somewhere in the 7.2-7.5 range. Longer term you want to replace water, which will lower both your CYA and your CH; a total of 1/4 to 1/3 of your water ought to do the trick. That would get your CYA into the 60-70 range and your CH in the neighborhood of 300-350, which is still on the high side but more tolerable.

Stop using the tabs, they are "trichlor" which adds 6ppm CYA for every 10ppm FC.
--paulr

 

[duraleigh]

Good morning, Todd, (How the heck did you get that username? There's about 50,000,000 Texans on here :lol: :lol: :lol: and I would think one of them would've grabbed it already)

Ditto what Paul says. Unfortunately, your pucks have to go. The white stuff on the stonework is almost surely calcium precipitate and will come off with a dilution of muriatic acid. Do it after the party....it'll probably take a couple of applications.

The scaling and piting on the pool surfaces are a little difficult to analyze from a pic but very, very likely are a result of what Paul said....too high pH, too high CH.

Once you make the commitment to reduce your CYA and CH thru draining, I would suggest you run your FC at elevated levels (say up around 8-10 with a CYA of 50) for perhaps as much as a few weeks to see if it improves the stains. I'm not overly hopeful it will, but it's a cheap way to find out if they're organic.

More likely, you may have to get a pro in to clean and rejuvenate the whole surface.

 

[KatyTx]

Thanks guys for your help. I drained about 1/2 of the water this morning and have been refilling. The pucks are gone. I have 6% bleach on hand so I can adjust the chlorine levels when the water gets to the skimmers. It looks like it will be 7:00pm or later so I guess I will let it run all night.

The scale is quite thick in areas. I used a hammer (yes, a hammer) to chip away at some areas and experimented with a 3:1 muratic dilution. The acid bubbled and I scrubbed, but it did not appear to remove any scale. Is this the process? How many applications should it take in a thin area?

I used the wire brush on the spots on the bottom of the pool to no avail. I'll jump in later with the goggles to check the texture. I'll try the suggestion to run with high FC levels after the party. No money in the budget for a restoration at this point.

One more thing. How do you normally drain the pool? I tied a weight to my vac cleaner to suck from teh bottom once the skimmers were dry. I see only three return lines: skimmer, cleaner (Hayward pool vac ultra), and spa. Where would the pool drains be plumbed to?

KatyTX... I figured it would be gone too. In any case, it is easy to remember! :-D

 

[PaulR]

The main drain and skimmer might be plumbed separately, in which case there should be valves at the pump end to control which is open how much. Or, the main drain could be plumbed into the skimmer, and a single suction pipe runs from there to the pump. In the latter case there will be some sort of arrangement in the skimmer to control the proportion of skimmer versus main drain. In my pool this arrangement is built into the bottom of the skimmer basket itself, which you orient in different directions to control whether it's skimmer-only, drain-only, or a combination.

If you have separate suction lines for drain and skimmer, you can obviously close the skimmer completely and then pump to waste just from the main drain. If your drain is plumbed through the skimmer that doesn't work, at least not in my pool. So I have a little sump pump that I use for draining.
--paulr

 

[KatyTx]

I drained 1/2 the water yesterday and refilled. The fill water CH is 110 and the pH is 7.5.

The results from this morning are as follows:
FC - 2
CC - 0.5
TC - 2.5
pH - 7.8
TA - 150
CH - 200
CYA - 40

I understand that the FC is low, and that the CH and CYA have decreased in relation to the amount of water that was replaced.

I do not understand why the pH and TA are still high. I expected the TA would also decrease in relation to the water replacement. Can anyone explain? In any case, I guess I need to lower the TA. Do I need to do this first since it affects pH?

I think I should bump up the FC now (as opposed to after I correct the TA/pH) to avoid algae growth. Is this correct?

 

[searayboater]

My bro in Houston has the same stonework around his spillover hot tub and he had the same scaling. He used a 50/50 mix of MA, green scrubbie pad and elbow grease. It eventually came off.

 

[JasonLion]

TA won't go down if your fill water has a high TA level. You should test the TA and CH levels of your fill water.

 

[KatyTx]

Hmm...

Fill water:
pH - 7.5
TA - 180
CH is 110

So, the TA may be pushing the pH up.

 

[JasonLion]

Yes, high TA levels will tend to push up the PH. You also need to watch for the CH level rising as you add water. CH doesn't evaporate, so it just accumulates in the pool.

 

[anonapersona]

In any case, I guess I need to lower the TA. Do I need to do this first since it affects pH?

I think I should bump up the FC now (as opposed to after I correct the TA/pH) to avoid algae growth. Is this correct?

Just lowering the pH with acid will work to lower the TA over time. If you have to do that a lot, that is, if the pH is getting to 7.8, then you lower it to 7.5 per Pool Calculator, and it rises back to 7.8 too fast and too frequently to suit you, then you may chose to lower the TA following the procedure in Pool School. As you add replacement water TA will rise again. So, your choice on that, just do keep pH in the correct range, whether you work at lowering the TA or not.

My fill water is 340 TA and I add a lot of water, due to evaporation on the waterfall, or maybe I still have a small leak, and so even though I did lower the TA to 80 at one point, it has crept back up to 110. DH still reports he easily swims with his eyes open under water at pH 7.7 and so I am not too worried about working to lower the TA again. I just monitor pH and at 7.8 I drop it to 7.5 or maybe a tad lower. It rises to 7.7 pretty quickly with the waterfall and spillover spa.

More important is the FC. You are correct, that is the key to algae prevention and so you need to jump on that right away. Adding chlorine after dark is good since it gives the chlorine a chance to sneak up on the algae when the algae is alseep and not multiplying.

 

[KatyTx]

...whether you work at lowering the TA or not.

I plan to do this, but not this week. Maybe next week after the pool party.

DH still reports he easily swims with his eyes open under water at pH 7.7 and so I am not too worried about working to lower the TA again.

Is it the pH that makes swimming with one's eyes open uncomfortable? If so, what is bad and what is optimal? My spillover spa is probably pushing it up. Unfortunately, I don't think my valve configuration will allow me to turn it off.

Adding chlorine after dark is good...

That makes sense. Any tips on when to run my filter pump? I have seen a few references to related to duration based on flow rate and pool capacity, and one post about running a few hours in the morning and a few in the evening, but I think it was addressing water temperature rise. It seems like running at night might slow FC loss as well as evaporation since your aren't breaking the surface during the heat of the day. My neighbor runs his at night. I can't comment on his success or lack thereof. I know he has had some recurring algae, but so have I. Your thoughts?

Signed,
The neighborhood BBB ginuea pig.

 

[Buggsw]

Todd, it all depends on what is best for you, when you run the pump. If you are worried about higher rates in the daytime, then set it to run at night.

Does it get real hot in Katy, TX? I live in Arizona and it gets beastly hot here. The rule of thumb I use is to run my pump 1 hour for every 10 degrees of air temperature. So, in the summer, I run it 10 or 12 hours per day. I usually have mine start at anywhere between 4 - 6 pm and run it the 10 - 12 hours. I prefer to run most of it at night because it seems to cool the water better and especially if you are aerating to cool the water, it's best to run it at night because of evaporation. Anyway, all this works very well for me and my pool and I'm able to keep my pool temperature at a max of 84 degrees when the high temps for the day are 116 or so. We like our water nice and cool out here.

 

[lovingHDTV]

Looks like you have similar fill water to us here in Round Rock.

I only add chlorine and MA to my pool. It is all that is needed when you have the high TA fill water. For CH I just manage it by keeping a lower TA until it hits 800-900ppm, then I do a water changed to get it back around 300. It takes a several swim seasons before it gets that high so its not too bad for me.

Enjoy your pool,
dave

 

[frustratedpoolmom]

If your pool is uncovered, and hour or two during the day at the very least, to help prevent FC dead spots...

 

[anonapersona]

Todd,

First, let me point out that I am still a novice at this, only had a pool 7 months now. That said, I do read a lot.

As far as pump run times, a co-worker suggested to run the pumps at night and only once, run the cleaner during that time, run the waterfall before everything else. I played with that, decided that I was not comfortable with no circulation all day long and algae on the waterfall has been an issue. I don't even know if electric rates vary at night, I don't think so.

So, currently, I run the waterfall at 7 AM to cool the pool as it is still nice outside then and any earlier and I notice the hum of equipment outside my bedroom. It goes only 30 minutes, that seems to be keeping the pool nearly too cool for me. Right after that, the Polaris runs for 1 hr to clean up whatever has fallen in the pool from the waterfall.

At 1 PM the filter comes on again, I finally decided that I was more concerned about dead spots where algae might be growing in the day with no circulation. It runs for 8 hours, I think I am supposed to go longer at this time of year (11 hrs was suggested) but the pool seems fine -- perhaps the running of the waterfall and the Polaris keep it stirred up a bit for that extra 1.5 hr they add. The filter runs until 9 PM, and during that time the Polaris runs again for an hour, currently from 4 to 5 but I really ought to change that to after the waterfall runs.

Were the pool any warmer I'd probably push the filter time into early morning and early evening. Then as fall comes I will probably run more in the heat of the day, along with more waterfall use then to keep the pool warmer.

One more thing, I've read here that after you use the spa, best to let it circulate through the pool to get the chemistry back in line, all the aeration plays with the pH and all the bodies use up chlorine. I was always surprised at how I was getting algae in the spa and I suspect that this will help both the deposits at the spillway and the algae.

 

[KatyTx]

Thanks to everyone for their help. I performed a quick check this morning and FC=6 and pH=7.8. I need to run to the store to pick up more acid. I got some borate test strips in the mail yesterday. I'll look into that next week.

I will definitely make a change to running the pump for some length of time during the early morning hours to cool the pool. My current temp is 88. Not at all refreshing, for me anyway. My system has only one pump which is currently on a 9:00-5:00 schedule. I'll probably run it for an hour or so after lunch and some more in the evening and see how it goes.