I currently use an automated Tab Chlorine System. After spending the last few days reading everything I can find on this board (which is a lot) I am having difficulty making an educated estimate for my Stenner needs. I am trying to maximize ease of use, not necessarily the most expensive route, but not really money adverse either.

I want to buy a system, Install it, and then tinker with flow-rates and such without going through an intermediate step of manually buying and dosing with liquid chlorine ... and the peak season is over anyway, so I still want to get a system in place now that can scale up next year.

So my questions:

1) My pool holds 30,000 gallons of water. How much chlorine will I be using on average during the peak months and what is the most I can store outside considering chlorine breaks down with time and temperature.

I live in Austin Texas :Austin summers are usually hot and humid, with average July and August highs in the mid-90s °F (34–36 °C). Highs exceed 90 °F (32.2 °C) on 109 days per year, and 100 °F (37.8 °C) on 12. This last year we had 27 consecutive days with 100-degree highs.

I know that their are all kinds of variables -- but is it reasonable to get a 30gal container, or is that clearly too big. It seems that most people are using 15 gallon containers ... is this a kind-of "magic" point between ease of use and chlorine disintegration?

1a) How long will chlorine be viable in this heat? (Assuming it is UV protected). I may use regular 6%, or may have access to 12.5%.

2) Which pump? It seems to me that I can do everything with the Stenner45MP1 Single Head Fixed Output Low Pressure Pump, for 10$ more I can get the high pressure -- is it safe to assume that my pool output is under 25psi? Or is 10$ good insurance?

Thanks in advance... I will certainly have more questions later about how to automate this with my existing electronics, but I want to get this part working first.

In Texas guessing at worst case you could be using 1.5-2 gallons a day of 6%, maybe even 2-3 gallons if you are having a pool party as well as extreme heat. In more typical conditions, most of the season just not the peak of summer, I suspect you will be under 1 gallon a day. Of course, if you are shocking the pool you can go way over that, but that can be added manually. You have some control over this. By raising the CYA level a little you can cut the chlorine consumption somewhat, which is often worth doing in those kinds of conditions.

Even with 6% at 2 gallons a day you will get a week out of a 15 gallon tank. If you raise the CYA level a little you should easily be able to get two weeks from 15 gallons. The 30 gallon tank doesn't hurt anything, but it is unlikely to be needed.

With 6% chlorine you are fine for two or three weeks. It will lose some strength at 100 degrees, but it won't be a big deal. With 12.5% you will have much more noticeable loses due to the heat and I would try to hold things to a week per fill or put the tank somewhere cooler. You can actually go longer, I am being conservative. But if you do go longer you may end up needing to adjust the feed rate a little higher to account of loss of strength towards the end of the tank.

What does your filter pressure run? Most pools will be under 25 psi, but with a 2 HP pump you might be going over that, depending on how your plumbing was done.

First, thanks for the reply... this board is very cool ... I hope to be able to support others too!
I don't know how to determine filter pressure ... I guess I need to look into that ...

I guess if I dig a whole, the 12% would be ok for 2+ weeks which seems like a nice workable schedule for me...

So that will be the plan for now ... I will get the 15 gallon and plan to bury it up to the pump...

Thanks again ...

Most filters have a pressure gauge right on the filter, used to determine when the filter needs backwashing/cleaning.

Just adding my thoughts.
Spend the extra to get the adjustable output pump.
I agree with Jason that you'll need 1½ to 2 gallons per day.
If you want to run your main pump 8 hours a day, you'll need an injection pump that's capable of delivering at least 6 gpd. The 45M2 is 10gpd which in the closest to your needs.
If you run your main pump 24 hours a day then you can get by with the 45M1 pump. Though I'd probably go with a slightly bigger pump any way.
I recommend getting the high pressure pump. It includes a check valve at the injection point.

Take a look at my last post in this thread. I uploaded a spreadhsheet that you may find useful. I have a 36K gallon pool. Close in size, but different geography. See if it helps. post320058.html#p320058

X2 on the adjustable pump for the flexibility, and you can always just leave it at 10 and treat it like a fixed rate pump.

I'd also go with the 100psi version too - it comes with a check valve at the injection point but I'm not sure if the 25 psi ones do (someone correct me if I'm wrong) - it'll give you an extra measure of safety.

Curious, did you ever install the system? I missed this thread, but I put one in last year and it was a sure fire way to dose chlorine at the right amount, every day. I have about 23K gallons and used around one gallon a day last summer. I had my CYA at around 45.