Questions about BBB

choots

0
May 22, 2011
19
Hi all, I started in on BBB late last year, but didn't really grasp everything then. My experience is much better this year, but I wanted to gather a bunch of my questions together into one place. Sorry for the length of this thread.

Background:
- Last year took possession of house with 15,000 gal Pool in MN.
- I completely cleaned the cartridge filter housing and cartridges last fall (loaded with Crud last year), using a cleaning solution which was mostly acid.
- Pool was winterized with mesh cover and we had a very late opening due to low temps (May 9th this year vs. Apr 3 last year.
- When opened we had a pretty green swamp - not as bad as some, but it was green, with lots of dirt and worms
- Did not lower the water level in the fall, also did not blow out the prop. Glyc. anitfreeze in the skimmer lines - probably a half-gallon each for two skimmers
- Had a poor excuse for a test kit - a 5 way HTH kit bought a couple years ago at WalMart. I learned from TFP that this kit is really inadequate, especially for testing FC and CC!

- I used Pool calc. and hit it with Chlorine at what I thought was a high level, but when I first started last week, I didn't quite understand the impact of CYA on Rec. FC.
- I had started with two 127 oz jugs of 12.5% bleach and then learned that I must shock well above that due to CYA/Chlorine chart.
- Knowing we used stabilized tablets for some time last year, I tested the CYA, but got wonky results - summarized below.
- Clearing the pool of algae took a long time, I started Monday the 9th and I brushed, scooped and ran the pump to filter 24/7 for at least the last five full days in a row.
- I bought 12% bleach (pool shock) from the home center, and then realized the 182 oz jugs of 6% at Walmart were cheaper and I went through like 16 big jugs.
- I only think I really got it cleared up overnight in after about two to three weeks. But now the algae has finally disappeared; the pool is really sparkling blue again.

Some comments about my CYA Level:
- First reading was 35 then I checked later and got 60 with older reagents;
- I ran out after this test and went a bought new CYA test reagent - new test kit.
- Two readings with new reagents warmed to room temp gives 40-45 and approx35
- I'll throw out the first results and say my CYA is closer to 35-40 (it's not super consistent)

Recent numbers:
FC - 6
CC <0.5
pH - between 7.2 and 7.5
TA - 120 (I have been reducing it slowly from 180)
CH - 210
CYA - 35-40

Now, some questions:
1) Should I increase CYA at this time? Say to 50? If yes, I have some left over pucks with stabilizer - what value should I target and how many should I expect to use to get there?
- I will say I like the idea of keeping CYA below 50 in case I have to use some pucks while we are away for longer periods.

2) Why did it take so long to clear? I had the chlorine level up for days and the pump running 24/7 the whole time.

3) I'm having a little difficulty keeping a chlorine level up though my CC <0.5ppm and my water is really sparkling clean, especially in the sunlight!
I think I passed the OFCLT, but questions came up:
- When should I be measuring the FC? After there's no direct sun on the pool? Or after the Sun has gone down and there's less light, or after there is no sunlight (when it's nighttime dark)
- When measuring in the morning, how much time should pass before taking a new measurement? If you have fixed criteria, I would expect fixed timeframes for comparison of results.
- Should I be measuring before sun comes back up - now like 5:00 to 5:30 am, or before there is direct sun on the pool (where it's light out but still very shady in the back yard)?

4) I had what I thought was high Alkalinity to start - 180. I've decided to continue to reduce to 100. Agree?

5) My filter was super clean at the start of the season - gauge read 9 PSI - now it's at 13. Would I have better luck maintaining chlorine levels if I cleaned the filters now instead of waiting till it goes up closer to 18?

6) How does Sunlight/UV remove chlorine? What is/are the chemical reaction(s)? I've searched TFP, but can't find a direct answer.

7) Since chlorine adds salt with every bottle, and I have an expensive stamped concrete surround and patio, I'm concerned about the salt causing damage on the concrete. What concentration would start to really cause issues? Should I be concerned? I don't know what my current salt levels are - don't know the general age of the water.

8) My stainless steel handholds and ladder appear to be somewhat corroded over the three to fours inches or so where they are held in the concrete - should I apply some jelly/oil product to these parts to prevent this? Water seems to collect in these holes, it's hard to avoid that.

9) I have a plastic white steps that are embedded in the concrete - I see a few small spots that are stained with what looks like rust. I think the vitamin C pill I tried on one helped remove improve stain, but the others look like tiny rust spots and were more concentrate/visible. I'm pretty sure the water was from a city source - possibly from a fire hydrant but don't know. It's not from a well I'm guessing. I only have a couple small ones, should I just keep using pills - I'd rather not risk lowering Chlorine too far.

10) We've had hot temps and we get Direct sun on the pool for about 11 hours a day right now. I lost 5 ppm FC yesterday and was surprised. Is this possible/normal for my pool? I was hoping that I'd get by with a quart or so a day consumption, but at this rate it will be much higher than that.

11) I'd like to avoid the algae bloom happening again over winter, which of the following would help the most?
- Remove leaves from mesh cover in later fall and after snow melts/ice thaws.
- Add chlorine through the mesh cover to increase levels and fight some algae prior to opening in mid April (i.e. no pump)
- Blow out the glycol instead of leaving it in the pool (organics which steal chlorine on opening)
- Vacuum fine debris to waste instead of to filter, or suck it out using an alternate pump, which I have ( I fight with my wife about this - she thinks that's what the filter is for - I say this just slows the process down and consumes more chlorine, because they are technically still in the pool water, just in the filter.)


Pool equipment: Sta-Rite Cartfidge Filter system, Sta-Rite Pump, 200+K BTU Raypak gas heater, 15K Gal. Vinyl pool

Thanks for your thoughts.
Choots
 
1) Yes, raising CYA is a good idea. It is still early in the season, and CYA will tend to go down a little over the course of the season, so best to get it to around 50 now.
2) There isn't enough detail to be sure, but I suspect it was because you didn't use enough chlorine.
3) Best to measure FC in the evening each day, but any consistent time of day will work. When you measure in the evening, it can be almost any time after the sun is off the water till late. But doing it in the morning, it is important to try and be consistent about what time you check.
4) Sure.
5) Clean the filter when it gets to 15.
6) Check out this post.
7) Don't worry about salt at all. The salt level would need to be far far higher than you will ever get it before there will be problems with concrete, stamped or otherwise.
8) Try marine grease.
9) Try a sock with many vitamin C tablets in it.
10) Might be normal. FC loss is much higher when it is very hot and sunny.
11) Fold back a corner of the mesh and add a little chlorine once a month. Also close late and open early.
 
Thanks Jason for all your responses.

Regarding the chlorination in winter, I think that might be pretty tough to do with two to three feet of snow on the ground and a foot of ice in the pool. I can see doing that after snow melts, so that would probably help. Also, in line with your recommendation, my wife wanted to open the pool earlier than I did because I didn't want to be maintaining it until someone was using it. Maybe I should listen to her more... :shock:

Regarding raising CYA levels, I have a left over supply of Trichlor pucks, about how many would you expect to use to raise the CYA 10 ppm in 15K gallons? I don't have info on how much is in each puck - it's only given in percentage, and no info on how heavy each three inch puck is.

Thanks,
choots
 
Just as an update, I added three pucks to the pool back in June and brought the CYA level to approx 47 which I'll leave there. I get pretty consistent FC levels that drop about 2-3 ppm on hot sunny days, so this is good enough. I use approx 40 oz of 12.5% bleach most days, but it's easy, and my wife loves the result.

Also, I've recently referred a friend here as he was having trouble with his concrete pool - he was getting algae blooms because he wasn't stabilizing and couldn't maintain FC easily, and had high CH levels due to using Cal-hypo shock weekly (or so) and still had cloudy water. Also, he was only running his pump like 4 hours a day. But he's read the Pool School and he sounds like he's going to be a convert!

Thanks for all the help. Count me as someone with a case of Sparklypoolitis!

Choots
 
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