Frustrated with pool chemistry readings!

I've had my pool for a while and haven't had any problems. This year, it was opened on Friday, and when we tested the water on Saturday, we were told by a local company going out of business that we were "locked". He didn't try to sell me anything, but told me to call the company who does our opening and closing.

I had another sample tested elsewhere and was told that it had similar numbers to all the other pool water she'd been seeing, and sold us a bunch of crap to add to get the numbers right. Among these was 3 gallons of liquid shock.

Still no Free Chlorine reading. So I called the opening company who assured me that I did not have any problem, and he advised me to add 5 pounds of shock, which I did. Still no FC reading.

I will be purchasing a better test kit this afternoon on my way home, but my most recent test - on a dip stick test kit are as follows:

Free chlorine = 0
Total chlorine = 1-3 (ideal range)
Alkalinity = 80-100 (ideal range)
pH = 7.2 - 7.6 (ideal range)
hardness = 250-450 (low)

Some other info:
18' x 36' Roman Shaped pool
DE Filter, currently running 24 hours/day.
Water looks pretty clear. There is still some algae in the pool that we will be vacuuming up, from opening.

My question is whether I have a problem or not. Obviously we need to complete the vacuuming from the opening of the pool (we vacuumed for many hours over the weekend and rinsed the bag out every hour). Beyond the obvious, from what I have read on the internet, it looks like we have a big problem and we need to superchlorinate the pool. Is this right? I did a calculation I came across and it sounds like I'll need 16 pounds of EITHER non-chlorine shock OR chlorine shock to fix the problem.

I want to know if this will do it or is it possible to need another 16 pounds. Also, how is this added? Mixed in a bucket of water one pound at a time? I read that it will corrode the metal in the pool to do it all at the same time. So, over how long should this be added? I don't know if this is even the recommended approach.

OH - and the other problem to note is that we have a Luau scheduled for 6/15. PLEASE HELP!

The kit we recommend is the Taylor K-2006 or 2006C which you can get through the link in my signature. It is not available locally. Repost with your volume and we also need to know your CYA level to be able to recommend the appropriate shock level for your pool. We do not recommend non-chlorine shock. Can you also please list exactly what all you have put in the pool -- meaning ingredients and not just 'shock' and someone here will better be able to advise you.

Welcome to the Pool Forum!

Thanks for the response. My pool is 26,500 gallons.

Here are my most recent stats:
Free available chlorine - 0.5
Total available chlorine - 1
Calcium hardness - 160
Cyanuric acid - 10
Total alkalinity - 80
PH - 7
Base Demand - 24
Copper - 0
Iron - 0
Total dissolved solids - 600
Phosphates - 1000

In the past week I have added the following:
10 lbs alkalinity increased
5 lbs stabilizer
3 gallons liquid shock
5 pounds powder shock

Any advice you can give me I will greatly appreciate.

One more thing - the water looks clear to me.

What are the ingredients of the liquid shock and the powder shock that you added? When did you add the stabilizer and how did you add it?

Go to Walmart and get several boxes of 20 Mule Team Borax (in the laundry aisle) and several jugs of plain, unscented bleach -- generic is fine.

By the way, "chlorine lock" is a term with no valid meaning. In practice, what pool dealers mean, when they use that term is either:

(a) "something is wrong with your pool water, but we have no idea what",

OR

(b) "we want an excuse to sell you some high margin pool chemicals".

You cannot have "Chlorine Lock" with a CYA level of 10. To add to what Ben said, "Chlorine Lock" is a false name for the condition that occurs when CYA, ie stabilizer levels are too high for "normal" chlorine levels (ie, FC3ppm or less) to work. This usually happens when someone has used nothing but Tri-Chlor pucks and their CYA level is well over a 100 ppm but are trying to maintain chlorine at 3 to 5 ppm. The answer is simple: Higher levels of chlorine, 8-15 ppm. But with a CYA of 10, that's not possible. So back to Ben's "(a)"--they haven't a clue. As he said, "Chlorine Lock" doesn't exist.