Chlorine Tab Too Much For This Pool?

[Patrick Black]

First of all I'm new to maintaining a pool. Just bought an Intex 15' x 42'' last weekend(Excellent deal @ Big Lots). Currently there about 3850 to 3900 gallon in the pool (will have to recalculate after the late night storm).

Last night I shocked for the first time using the hthpool product and put in 6 oz of shock (added ph minus prior to this to lower the ph). About an hour after shocking the levels were in the 5ish range for the Total Chlorine (couldn't find a test for free and Combined).

Retested a little while ago and the Chlorine levels dropped way back down to the .5 to 0 range (below recommended levels).

I had purchased the 3in puck to put in but I'm not sure if this is too much for that pool. I just added more ph minus as the ph was still close to 7.8 (just below based on the color of the test). I put in less than 3oz so I don't overshoot the goal of 7.5.

So what say you experts and experienced pool maintainers?

Edited June 5, 2010 by Patrick Black

[PaulR]

Chlorine is a consumable; you need to replenish it as it gets used up. You have a couple different choices.

One is to use the 3" pucks. These are "trichlor" (sodium trichloro-s-triazinetrione) which is chlorine bound up with stabilizer (cyanuric acid, CYA). These work great at first, once you work out how to set the floater so they dissolve at the right pace. However, while the chlorine is constantly being used up, the stabilizer is not. Eventually the water will be over-stabilized and the chlorine will become ineffective; at that point you would need to dump the water and refill. In 3900 gallons I estimate this will be every 8-10 pucks. How long each puck will last is hard to say, probably about a week. In some latitudes, this would be a whole season, so it might be the easiest approach.

Another approach is an adaptation of Nitro's Approach to Water Maintenance which was originally written for hot tubs but can apply to small pools as well. For around 3900 gallons, you want 2 lb of dichlor (this is sold under various brand names but the ingredient should be 100% sodium dichloro-s-triazinetrione). I'd guess about 1/3 cup daily until you've used up the whole 2 lb would be about right. After that, you need to STOP using dichlor and switch to (regular unscented household) bleach. You'd probably want around 2 cups per day, fine-tune that according to what your test kit tells you the levels are. Make sure your chlorine level never goes below 2ppm; that is, right before you add bleach, the level should be at least 2ppm.

So, the second approach is a bit more work, but it saves you having to dump the water if the season goes more than 8-10 weeks or so.

--paulr

[Patrick Black]

Another approach is an adaptation of Nitro's Approach to Water Maintenance which was originally written for hot tubs but can apply to small pools as well. For around 3900 gallons, you want 2 lb of dichlor (this is sold under various brand names but the ingredient should be 100% sodium dichloro-s-triazinetrione). I'd guess about 1/3 cup daily until you've used up the whole 2 lb would be about right. After that, you need to STOP using dichlor and switch to (regular unscented household) bleach. You'd probably want around 2 cups per day, fine-tune that according to what your test kit tells you the levels are. Make sure your chlorine level never goes below 2ppm; that is, right before you add bleach, the level should be at least 2ppm.

So, the second approach is a bit more work, but it saves you having to dump the water if the season goes more than 8-10 weeks or so.

--paulr

What's the difference if I just used straight bleach right off the bat? Oh and after I add it how long usually till it's safe to swim.

Thank you for your suggestions.

[polyvue]

Another approach is an adaptation of Nitro's Approach to Water Maintenance which was originally written for hot tubs but can apply to small pools as well. For around 3900 gallons, you want 2 lb of dichlor (this is sold under various brand names but the ingredient should be 100% sodium dichloro-s-triazinetrione). I'd guess about 1/3 cup daily until you've used up the whole 2 lb would be about right. After that, you need to STOP using dichlor and switch to (regular unscented household) bleach. You'd probably want around 2 cups per day, fine-tune that according to what your test kit tells you the levels are. Make sure your chlorine level never goes below 2ppm; that is, right before you add bleach, the level should be at least 2ppm.

So, the second approach is a bit more work, but it saves you having to dump the water if the season goes more than 8-10 weeks or so.

--paulr

What's the difference if I just used straight bleach right off the bat? Oh and after I add it how long usually till it's safe to swim.

Thank you for your suggestions.

You can add stabilizer (aka cyanuric acid or CYA) separately and just use straight bleach to chlorinate. When you add granular or flaked CYA directly it may take a while (several days) to dissolve sufficiently so that it shows up in a test. The liquid form of CYA (often called "conditioner") dissolves much faster but is more expensive. See the column for "minimum FC" in one of the CYA/chlorine relationship charts below.

http://www.poolforum...hread.php?t=365

http://www.troublefr...cya_chart_shock

Assuming good circulation in your pool, wait 30 minutes or so after adding liquid chlorine before swimming. That will give the pump/filter time to disperse the chlorine.

[chem geek]

What's the difference if I just used straight bleach right off the bat?

If you were to use unstabilized chlorine, such as bleach, with no CYA in the water, then the active chlorine level would be far too strong by orders-of-magnitude by a factor of at least 10 or more.