Please Help / Advise

[DavidD]

24k gallons could be right but I'd guess around 22k. Either way, one gallon of 6% bleach should raise your FC by ~2.5ppm. High CH can cause scaling but sometimes shocking with cal-hypo with high CH will cause cloudiness, however I'll bet your issues all stem from the algae.

[waterbear]

A couple of thoughts.....

If the DPD powder is black I would not trust the resuts....get a cheap OTO kit (turns yellow to test for TC) and check the level until Ben's kit arrives. IF the OTO shows high levels of TC around where you are testing now then you very well might have a huge chlorine demand going on right now becuase of the bacterial breakdown of the CYA. This is going to take a LOT of bleach or shock to eat up the 'poop'.

Check the third post in this thread for Ben's advice
http://www.poolforum.com/pf2/showthread.php?t=1001

ALK of 120 is fine.

Your Calcium level is is only a concern if you have very hard fill water. Cal Hypo does add some calcium to your pool but not that much.
You might want to test the Calcium hardness just for peace of mind. If it is much above 400 then raising your pH to 7.8 might cause some cloudiness but as Ben said in the above thread your filter should take care of that. Once again for peace of mind, you might want to stick with just bleach to shock.

It might take some time and a lot of bleach to kill the algae and clear the pool but it will and you will be swimming soon.

Post a recent set of full test results and that will help to see just where you are now.

[meajma]

Thanks again Dave, and Waterbear !

I do hope that my 234 kit arrives soon so that I can post some results with confidence, although from what I'm reading in these forums.. the numbers are making sense in that respect.

I have read that thread waterbear, and that's what makes me think that I have a similar situation.

Either way, I'll try to get another set of results posted by tonight to see how thinhgs are progressing.

It's great to have this type of feedback here. I'm thankful for all the help that you folks offer.

Mark

[meajma]

OK so I left work early in order to test the pool again. Unfortunately I still am using the old 232 test kit. I'll pick up a OTO kit to verify TC when I go get bleach..which will be in a few minutes.

Results were pretty much as expected..

PH 7.6 (I had added a box of BORAX last night before shocking)
FC 5.0 (better than yesterday, shocked with cal-hypo last night)
CC 7.0 (makes sense that it increased, after shocking last night)
ALK 170
CH 190
CYA 0
Temp ~65 C but that's a feel guestimate, it was ~80 deg F here for most of the day.

So, I'm off to Naamco right now to get some bleach. I'll check for any replies when I get back. Will probably be gone for ~1 hour.

Thanks again for all your help!

Mark

[prh129]

If you got the FC up to shock levels, I would expect your CC to go down not up. I wonder if you're not getting the FC up high enough.

[meajma]

I mentioned that I shocked with two bags of HTH cal-hypo last night, so I would have expected that to make the FC much higher than 5, as it was when I tested this afternoon.. SO. unless my thinking is backwards, wouldn't that mean that the FC was higher, then used up to a certain extent, making the CC level higher..?

I could be totally wrong, I'm simply making assumptions..

I just bought two 5 gal drums of liquid bleach (12.5 % sod hypo)..

How much should I dump in there..?

[prh129]

The text below is from "Water Chemistry for Swimming Pools" that is linked in one of the threads in the "using chlorine" section. My understanding is that shocking = superchlorinating and if you succesfully shock then CC should go to 0. From the text below, it says to do that FC needs to be 10x of CC which would be 70 ppm in your case which sounds way too high. I don't have the experience to suggest what you should do so I won't.

*************************

Breakpoint Chlorination is the process by which combined chlorine and some organics are "burned out" of the pool by addition of large amounts of chlorine. The reaction of chlorine with ammonia to form chloramines occurs in several stages with free chlorine consumed at each stage. If enough chlorine is added to the water the total chlorine residual will rise to a point that forces the reaction of chlorine with ammonia to go rapidly to completion. Compounds of nitrogen and chlorine are released from the water and the apparent residual chlorine decreases. The point at which the chlorine residual suddenly drops is called the breakpoint. When enough chlorine is added to pass the breakpoint, combined chlorine compounds disappear, eye irritation potential and chlorine odors disappear, and the chlorine remaining in the water is all in the free state.
Superchlorination: In order to prevent buildup of chloramines in the pool it is necessary to periodically add large amounts of new chlorine in an effort to pass the breakpoint. Public swimming pools should be supechlorinated about once a week. The amount of chlorine needed to reach the breakpoint will vary depending on the amount of organic material introduced by bathers and on the level of free chlorine maintained in the pool. If the amount of combined chlorine is known then the amount of new chlorine needed is ten times the amount of combined chlorine. When combined chlorine residual is not known, superchlorination is accomplished by adding 10 ppm of new chlorine to the pool. Ordinarily calcium hypochlorite at a dose of at least 1 lb. per 10,000 gallons is used for superchlorination. The chart below shows the amounts of various chlorine compounds which can be used to introduce 10 ppm of chlorine to the pool.
Chart No. 9 - Superchlorination
(Amount Needed to Introduce 10 ppm)
Type of chlorine GALLONS IN POOL
15,000 20,000 25, 000 50,000
Sodium Hypo 1 1/4 gal. 1 2/3 gal. 2 gal. 4 gal.
Lithium Hypo 3 1/2 lbs. 4 3/4 lbs. 6 lbs. 12 lbs
Dichlor 2 lbs. 2 2/3 lbs. 3 1/3 lbs. 6 3/4 lbs.
Calcium Hypo 2 lbs. 2 1/2 lbs. 3 1/4 lbs. 6 1/2 lbs.