Calcium Hypo or Trichlor?

[goldslinger]

Hello, All!

I like to use trichlor tabs in my chlorine feeder but My CYA level is approaching 60ppm, so thinking of going to Calcium Hypochlorate which is cheaper anyway. As shown in signature, I have an inground vinyl, 36,000 gallon pool and am having problems keeping the PH up anyway. I think some of that problem is using the trichlor, so if You all think I have some calcium room, I would like to switch to the cheaper calcium to help pocket book and ph.

test 7/30/12

free chlorine = 14 (elevated by purchasing cheap Walmart calcium pucks that turned to mush in chlorine feeder and gushed out of jets).
Total Chlorine = 14
PH = 7.4
ALK = 105
Calcium = 230
CYA = 56

I have some gallon jugs of chlorox, but don't like the hassle of adding each day, and buying them at Sam's and lugging them home, but use them to boost chlorine after bad weather, heavy swimming, etc.

What would You all recommend before I commit to a big bucket of chlorine pucks?

Gary

[AnnaK]

Please clarify: is your pool 36,000 gal (per post) or 24,000 gal (per signature) ?

I would not go with cal-hypo in a vinyl pool.

Have you checked with the pool stores in your area to see if they carry liquid chlorine in 5 gallon carboys? The concentration is 14% when manufactured but degrades to around 11-12% during storage, still twice what regular bleach is. I pay around $15 for a refill in my area. You'd have to add approximately 1/2 gallon daily to keep your FC at a minimum of 3 ppm.

Depending on how much longer your pool will stay open you might be able to augment the chlorine demand with trichlor. Yes, it does drop the pH and increases CYA but if you don't make it your primary chlorine source those changes will be relatively minor. You know how to raise pH and bringing the CYA up a few more points won't be a tragedy this late in the season.

Having a pool means having to add its maintenance expenses to our annual budgets. If you're shooting for "cheap" you will eventually get what you pay for and then you'll pay for cleaning up what cheap created. Testing the water and adding some chlorine every day isn't much of a hassle though I agree that buying bleach in gallon jugs and having to dispose of them can be inconvenient when you have a large pool. Try to find the carboys, they make life easier.

[Watermom]

Anna and I see this a little differently and thus have a little different advice for you on this. (Although I agree with her that finding higher concentration liquid chlorine in carboys would be another good option.)

Of course, vinyl pools don't NEED calcium, however, I think it is ok to use some cal-hypo in a vinyl pool as long as you don't let the calcium hardness get too high. I know that Al (co-moderator Poconos) uses cal-hypo sometimes in his pool. With probably not more than around a month left of swim season, I don't think using cal-hypo would take your level past 400 by summer's end, but again, you would have to watch it. You'll drain some upon closing and then add more water next spring which would dilute the calcium reading some at that point. UNLESS --- your fill water is high in calcium. If so, then you won't be able to dilute it any and probably shouldn't use it.

Having said all this, i DON'T think you can get away with using cal-hypo exclusively for a full summer or your calcium hardness reading probably will get too high. I think you'll have to see where you are CH-wise next spring before you can decide how much you can use it then as well.

[goldslinger]

Thank You, Ladies!

I think I am starting to get the hang of this. I just need some type of chlorination in slow release form that doesn't have stabilizer in it.

Thanks again.

[AnnaK]

You might consider a salt water chlorine generator (SWCG) which converts the salt you put in your pool water to chlorine. You add stabilizer separately to the level required by the SWCG's manufacturer. I don't have one but many people here do and there are many posts about them on the forum that you can search for.

[waterbear]

I believe you wanted to substitute cal hypo tabs for the trichlor tabs in the feeder or floater. THAT CANNOT BE DONE!!!!! Cal hypo tabs cannot be used in a chlorine feeder or floater (except for special vented united specifically designed feeders designed for them and usualy only used on commercial pools). The tabs sold for residential pools are designed for skimmer use, dissolve very fast (in a day or two) and have a lot of binders that leave a lot of goo behind.

I just need some type of chlorination in slow release form that doesn't have stabilizer in it.

This does not exist. There is only 1 form of chlorine used in pools that is slow dissolving enough to use in erosion feeders and floaters and that chemical is trichlor, wich is a chorinated isocyanurate--a chemical made from chlorine and cyanuric acid. When the chlorine is used up the cyanuric acid (stabilizer) stays behind and builds up at a rate of 6 ppm CYA for every 10 ppm FC added by the trichlor.
All forms of unstabilized chlorine (and the other form of stabilized chlorine -- dichlor -- are either fast dissolving (compared to trichlor) or liquid.

If you want to use an unstabilized chlorine and have its addition more automated so you do not have to add chlorine daily then you need to look into either a SWCG (your best bet for a residential pool) or a chemical feed system such as a peristaltic dosing pump for liquid chlorine (not that expensive but you need a storage tank for the chlorine and the units do require regular maintenance to keep the running and the tubing needs to be replaced on a regular basis) or a special vented feed system for cal hypo granules (expensive and hard to find for residential pools).

The peristaltic pumps sound attractive because of the price but I have worked with these feed systems on commercial pools (both with and without ORP control) and they do require almost daily checking and regular maintenance so a SWCG is going to be less maintenance once you get it set up. properly.

NONE of these options are going to have any effect on how often you test or balance your water, btw. You still need to test chlorine and pH daily (or at least every few days) TA weekly, and CH and CYA monthly. (If you use cal hypo or have very hard fill water you might need to be testing CH weekly).