Making sense of when I can/should/shouldn't use the chemicals I have onhand (prior to finding TFP)

JohnGn

Active member
Sep 28, 2019
31
St. Louis, MO
I've owned a pool just two years, and discovered this site just this morning. (I might have joined a while ago for the pool math section, but didn't see the light until now)

In those two years, I have had pretty darn good luck with the pool, taking care of almost everything myself by using other online resources and also getting a crash course in pool maintenance from the guy who put in my new vinyl liner. By "good luck," I mean very few instances of cloudy or green water, easy to maintain FC levels, chemistry always matching up with the pool store testing using just my HTH strips. Ignorance is bliss, I suppose, right?

Anyway, the reason for this post is to ask the experts about a couple things that are pretty specific. For example:
  • I have a tub and a half of Trichlor tablets purchased from Sam's. This is what I've used since day 1 for maintaining FC. I heard on a TFP video that Trichlor can cause issues or something. What issues? Should I stop using the tablets? Can I just use them up first? I assume I would use liquid chlorine to replace them. How much? I'm sure the quantity needed is based on the required increase in ppm of FC per X gallons of water. Can I use just regular cheapo bleach? If so, how much is needed to raise FC by what amount? I can also buy 10% LC at a pool store for $3.40 per gal., so I'd use less per dosing. Seems cheap enough, right?
  • I have about 8# of cal-hypo shock left from a big box I bought. My SOP has been to shock using 2# about once every week or 10 days or so as long as the FC numbers are still good and the water is clear. I shock or double shock at the slightest inkling of an issue, and typically within 12-24hrs, any issues have been resolved. Should I just go ahead and keep doing that until my supply of this powdered stuff is gone and THEN start my maintenance using the SLAM procedure?
  • I recently purchased two kinds of liquid chlorine. One is 10% (comes in a bulk 5gal tote for about $3.40 per gal) and one is 12.5% in one-gal containers that were $3.00 on sale. Is there a big difference I should know about when it comes to adding the right amount of liquid chlorine? I know the main thing is to test using the TF-100 or Taylor FAS-DPD kits. I will be buying one shortly. I guess I'll essentially be flying blind until I have a kit that tests at SLAM levels, so maybe I already answered my own question.
  • And finally, here's a goofy question: I had a green pool for over a week recently and of course nothing cleared it up except liquid chlorine in a MASSIVE dose. My question is: When is it safe to go back into the pool? My test strips all indicate 10ppm FC (or higher, who knows, right?) and my PoolMaster liquid test kit only goes to 5ppm and the color is way above that. Is it OK to swim at a high level, just for a few minutes to, well, take a dip? (For reference, the massive dose I added to my 18,400gal pool 48hrs ago was 10gal of 10% liquid chlorine. Pool is crystal clear now, of course!)
Thanks for your wisdom and comments.
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Save the tablets, they will be useful for if you take a trip, or if you need to bump your CYA a bit. From now on though for regular chlorination you’ll be using liquid.

Without a CH test number it’s not possible to advise you on whether you should use up your cal hypo or not.

You can use thePoolMath app to estimate chemical doses based on LC strength.

Regarding swimming, again without test results we can’t advise on whether or not the chlorine levels are safe for swimming.
 

JohnGn

Active member
Sep 28, 2019
31
St. Louis, MO
Save the tablets, they will be useful for if you take a trip, or if you need to bump your CYA a bit. From now on though for regular chlorination you’ll be using liquid.

Without a CH test number it’s not possible to advise you on whether you should use up your cal hypo or not.
Thanks! So, the tablets add CYA? It's not listed as an ingredient on the tub.

Also, my CH has always been in the "ideal" range based on test strips and pool store testing. I think I added some CHI early this season because my numbers were low and I have a water softener.
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Thanks! So, the tablets add CYA? It's not listed as an ingredient on the tub.

Also, my CH has always been in the "ideal" range based on test strips and pool store testing. I think I added some CHI early this season because my numbers were low and I have a water softener.
Tablets are Trichlor - trichloro-s-(I cant spell the rest off the top of my head.)
For every 1 PPM worth I’d free chlorine they add to the pool they also add .5 PPM CYA. Problem being that the chlorine gets used up, the CYA stays.
 

mguzzy

Gold Supporter
Once you get your test kit and post some numbers then the gurus will be able to make a more definitive recommendation. Otherwise we are flying as blind as you are. That's why a good test kit is important, and one that we all use so we are on the same testing standard.
 

Teald024

TFP Guide
Hello and Welcome (back) to TFP!!

You're right, ignorance is bliss. But now knowledge of pool care will become bliss. You may have to relearn a lot of what you already know about pool care. One of the main tenets of TFP is to test the water ourselves and only add what the pool needs. Also that we know what each chemical does and how it effects the pool chemistry.
First thing is the need of a quality test kit. I prefer the TF-100 from TFTestkits.net. This test kit will measure all the important chemical levels so we know where we are starting from. The TF-100 is also setup to include appropriate reagent bottle sizes that best fit our uses. Don't get sticker shock and don't buy on price alone. I promise the TF-100 kit will pay for itself this first season. Those test strips aren't accurate and won't cut it. As you said, you are flying blind without a proper drop based kit.

Those trichlor tabs.... what issues? they contain a lot of CYA. A lot of CYA is bad. You should stop using them for now and switch to liquid chlorine. Hold on to the trichlor tabs since they can be useful under the right circumstances.
How much liquid chlorine will you need? You can use PoolMath to help figure this out. For now we can assume the pool will loose about 3ppm of chlorine a day. This is normal on a perfectly clean and clear pool. By knowing the strength of the liquid chlorine (bleach) you can figure out how much to pour into the pool.
The active ingredient in liquid chlorine (bleach) is sodium hypochlorite. Any strength is fine to use, but the stronger it is the less you will have to pour and carry around. Any type, from cheapo to whatever. You just don't want to have any undesirable additives. The stuff marketed as bleach may contain other stuff that may be harmful or annoying at the least. No scents, no splashless, no chlormax technology, nothing with "Blue" in the title. Many times it ends up being the dull boring labeled stuff. You just want the cheapest per unit of chlorine. Many people like the bulk totes. If you can handle them, then do for it.

The cal-hypo can be saved for future use. Until you perform your testing, we can't say if you should use it or not. A vinyl liner pool usually doesn't care what the CH levels are on the low end. Since you are on softened water, you may need to adjust a bit. The TFP does not involve weekly or regularly "shocking" the pool. That is B.S. nonsense carryover from a system that is based on a "dump and hope" process." Don't do this going forward. If you need to clear algae, we will show you how.

And finally the goofy question... You NUKED the pool with that huge dose of LC. Potentially 85ppm or more into the pool. DO NOT swim in that. That is WAY too much for a single dose. You would have been much better off using that same 10 gallons and spread it out. You should have followed our SLAM Process. This is not used for regular weekly maintenance. The SLAM process basically raises the chlorine level and then maintains it there until the pool is clear.
You can swim in the pool if the chlorine level is below the SLAM level per the FC/CYA Chart, you can see the bottom and pH is in range. You won't know the FC or CYA until you get the quality test kit. It will be few days at least for the FC to drop to acceptable levels.
 
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