CH Questions

[medvampire]

Good morning all
My numbers

Free Ch 3 (DPD method)
Total CH 3 (OTO method)
TH 250-260
ALK 160-170
CYA 20-30
PH 7.6

Wal-Mart 5 way test and DPD tablet method.
I posted some testing questions in the testing forum now some chlorine usage questions.
When I bought the pool of course I got pool stored and bought a bunch of stuff I didn’t need but I would like to use them up before I switch to the BBB method. I now have a few questions.

• I work nights and I am in rotation at the hospital where I work for 7 days at a time. I am not too whoopee about letting any one else do the pool chem. using the BBB method. I get around 8 hours a day at home so I would rather spend my time sleeping. Can I use pucks in the feeder during that time and BBB when I am off rotation?
• Once the pool gets stable will the chlorine demand be constant enough I could pour off pre measured amounts of Clorox and have them pour them in when I am not home?
• Could I keep pucks in the feeder and have them toss a bag of oxy shock (got a few bags when I was pool stored)on day 3 of my rotation as a method when I can’t adjust the bleach going in the pool?

Thanks in advance
Steve

[prh129]

Your numbers look pretty good although the alkalinity is high. I don't know that you need to do anything about that for now so unless someone suggests otherwise I would let that be for now.

Are you able to test for CC? As long as CC stays below 0.5 ppm you don't have to shock so you can just keep the chlorine level where you are. If you use pucks, they contain chlorine and CYA so they will make your CYA level rise. As CYA levels rise, then you need to bump up the chlorine levels for them to be equally effective as they are now - you can look at Ben's best guess chart which is stickied in top of the chlorine thread to see how cl relates to CYA.

If your pool usage is regular (meaning you don't have 20 people in it one day and nobody in it the next day) then you should be able to measure out amounts of bleach for people to put in for you. Sunny days will cause chlorine to break down so you will need more than when it is cloudy. After a couple of weeks of testing you should get a good feel for it. You should be able to use the OTO test as a quick and dirty check on the pool frequently to let you know where the chlorine is at. Once a week or after heavy usage you should check for FC vs. CC.

I'm not familiar with the oxy shock so I can't advise you there. Maybe someone else here can. If you plan on using pucks, you shouldn't need to add anything unless the CC level gets above 0.5ppm.

Peter

[medvampire]

The useage is 2 boys and my girl friend while I am in rotation. I may have my g/f do a DPD fc and adjust the amount of cl she pours in each day. I just dont want the kiddies getting hurt by the chems. I may just build a chart thet if the fc is x then add x amount of clorx to the pool. She grew up with a pool and her pop just threw pucks in the skimmer so I am fighting that ideal with her.
Thanx
Steve

[waterbear]

Several observations...
First, using trichlor pucks will cause your CYA levels to rise. Not a problem now but it can become one. If you want to use a puck to maintain your FC occasionally that should be fine as long as your CYA levels are low. Once they rise above about 50 ppm I would not use pucks anymore. Be aware that they can cause your pH to drop.

You are using a N2 and many people with them run the FC at .5 to 1.5 ppm. I notice you are not. N2 is a copper/silver system. The main 'advantage' to adding metal ions to the water is to allow running lower FC levels. (I have 'advantage' in quotes because this can very easily and often does become a dangerous disadvatage of not having enough residual sanitizer in the pool to keep the water safe.) The copper comes from copper sulfate and the silver from silver nitrate..The N2 system is just an erosion feeder for the copper and silver compounds. for more info on copper and silver read this thread
http://www.poolforum.com/pf2/showthread.php?t=98
My advice is to save money on the N2 replacement cartridges and take the system out of your plumbing (or at least run it without a cartridge). It really doesn't do all that much good for all that it costs to run. SAve yourself the $160 to $220 a year the replacement cartridges will cost you!

The only way to get to know how much bleach your pool will take to keep it sanitized (and how much acid or borax it will take to keep the pH in line) is by testing these 2 parameters daily and keeping a record of how long they are in the proper range and how much of the proper chemicals it takes to get them back in range when they go out. It's a learning curve and you soon reach a point where you know that if you put in x amount of bleach every n days and y amount of acid every m days your pool will be fine under normal usage conditions. Do a bit of work on it now and you will have much less later once you know what is normal for your pool. Your bleach usage will be best once your CYA is in the 30-50 ppm range. Then shoot for 3-6 ppm FC and shock to 15 ppm when you get CC or cloudy water.

Finally about MPS or oxyshock. It will not remove CC. the idea is to get a residual of it in the pool to burn off organics before they form CC. MPS will test as CC on a DPD test and as TC on an OTO test. This makes it very hard to know if you have CC or residual MPS in the water. It is also not as good an oxidixer as chlorine and can have adverse affects on the pH. It has no true advantage in a chlorine pool. It is best used with bromine where it will actually reactivate the bromine bank into hypobromous acid...the active sanitizer in a bromine system. MPS is NOT a sanitizer so if your chlorine is too low adding MPS will NOT sanitize the water!!!!!!

[medvampire]

First let me say thanks for taking the time out of your schedule to answer questions here. I am getting a lot of great info by picking your brains and doing a lot of reading. I have a pretty good understanding of basic chem. and am in the process of gaining understanding of pool chem... Inorganic chem. was tough for me in college and I still have concepts flying over my head.
About the N2 I got “pool stored” when I bought the pool and after a little reading on what it was realized that 0.5 ppm cl wasn’t gonna cut it. From work in the hospital lab I know that the low levels of silver and copper would have little kill factor. I have seen many eye and ear infections from the above ground pools here so I wanted a good kill factor. I didn’t plan to waste my money next year on cartridge but buy one of Ben’s kits. I will not replace the cartridge but leave the vessel in line because it has a puck feeder.

Let me pick your brains a little more ……
As for shocking I was “pool stored” into thinking I could use Oxy Shock and not need to shock with bleach. I dumped some in about 3 weeks ago could this still be hitting my FC DPD readings?
Is it possible for me to create a chart using the OTO test with my CYA level I could hand my future wife and she could dump Clorox in while I am in rotation? (I finely got her convinced that Clorox is a good thing and she agreed to dump it in based on something simple if it works.)
Can I have her use AquaChem pH Decreaser (sodium bisulfate) and then use muriatic acid when I am home? (She won’t touch muriatic acid)
I understand the need to “shock” the pool but the practice of shocking just because the planets have aligned, I get a tarot card with a pool on it, or the pool store guy told me to is hog wash? Wait for CC to get over 0.5 or a whiff of motel pool smell?

I am trying to make it as easy on her as possible to switch to BBB when I am on rotation for a week at a time. I get about 7 to 8 hours at home each day. We cross paths for just a few moments each day so not much time to talk about the pool. I am gonna try to set up the chart Saturday for her. I come out of rotation at 7 Friday morning (yyyyeeeesssss!!!!)
Thanks
Steve

[prh129]

Is it possible for me to create a chart using the OTO test with my CYA level I could hand my future wife and she could dump Clorox in while I am in rotation? (I finely got her convinced that Clorox is a good thing and she agreed to dump it in based on something simple if it works.)
Can I have her use AquaChem pH Decreaser (sodium bisulfate) and then use muriatic acid when I am home? (She won’t touch muriatic acid)
[FONT=Arial][FONT=Courier New][COLOR=black]I understand the need to “shock” the pool but the practice of shocking just because the planets have aligned, I get a tarot card with a pool on it, or the pool store guy told me to is hog wash? Wait for CC to get over 0.5 or a whiff of motel pool smell?
FONT]

Yes, you should be able to make a chart for OTO readings vs. amount of chlorine to add.
You should also be able to use the pH decreaser but you may find that you don't need to. I have a 24' round AG and my pH stays pretty stable using bleach.
Right on the shocking - if you maintain your daily chlorine level you shouldn't need to shock (unless you have a lot of people over one day) but the CC level will show you if and when you need to shock. The smell should be a sign to test for CC. Good luck!

Peter

[medvampire]

Peter
Thanks for the input and I started a chart but decited to teach my 13 year old how to use the bleach calc program( great tool, many thanks to the programmer). I have do am oto test and PH and adjust the cl based on the software and tell me about the PH. Just dont feel good about him messing with muratic acid (wicked stuff). I will test the free cl 1 or 2 times a week just to make sure I dont have any CC and "shock" only when nessary.
Thanks again
Steve

[prh129]

Sounds good Steve.

I have a 24' round AG and in the last two months, I have not had to lower the pH at all - it's been pretty solid around 7.3-7.4. As long as you're keeping up with the chlorine you should be fine. Enjoy the pool!

Peter

[medvampire]

I am fighting a high ALK of 190 so untill I can lower it by acid / aeration I am adjusting weekly. I start at 7.6 and creep to 7.8 with in week. I will probly pick up some more acid week after next when I have a few days to watch it closely and drop that pesky alk.
Thanks
Steve