Trichlor tabs while on vacation, how many?

[Killer95Stang]

So we are leaving on a cruise and will be gone a total of 10 days. Right now the pool is perfect and I've never had algae (knock on wood), but because we are planning on being gone so long, I'm worried about the rise in PH. My solution, was to purchase an Aligator headed Tab dispenser and just try Trichlor while we are gone. Since I'm sitting at 70 - 80 ppm CYA, I figure 5 tabs will only take me to 90 at most (2ppm per tab), which is right at the limit for a Salt water pool in our hot CA weather (probably be in the 90's degree wise while we are gone). My big issue is, I have no idea how much chlorine / acid will get added to the pool every day with 5 taps in the dispenser. Will I over chlorinate or crash my PH? My alternative is to do nothing, bring my PH to 7.2 before I leave and turn off the waterfall that runs for 5 minutes 3 times a week.

Suggestions?

Water tests, cause you know that is the first question....

FC - 8
TC - 8.5
CC - .5
Salt - 3500 (taylor)
Ch - 750 (managed with MA)
Borates - 40-50ppm
TA - 60
CYA - 70 - 80ppm
PH - 7.5
Water temp - 80

 

[mknauss]

Effects of Adding Chemicals will give you the FC and pH changes for the trichlor. The wildcard is how long will it take to dissolve.

Leave the waterfall off while you are gone.

MA does not manage CH - FYI --

 

[Oly]

Estimate 10 days to fully dissolve 5 pucks in a floater.
Calculate how much FC in 5 pucks for your pool volume.
Divide by your expected daily FC loss.
See if you are close.

You can raise you FC to shock level with liquid before you leave.
Also you can pre fill some liquid chlorine doses and hire a neighbor to add it to your pool 3 or 4 times while you are gone.

 

[Killer95Stang]

so after a little research, I'm getting 8oz weight per Tab which give me a maximum addition of chlorine of 14ppm for my 20K pool. If I take into account that I lose about 2 - 3ppm when it is really hot outside and no real clue how fast 5 tabs will disolve, I might be better off just leaving everything as is and letting my PH get a little high while I'm gone. Too many variables in how fast a tablet dissolves to start worrying about it now.

When I say I manage my CH with MA additions, I mean, by keeping my PH between 7.2 - 7.6, I don't get scale build up in my pool. Living in CA which usually has little to no rain and high CH fill water, I just learn to live with CH between 800 and 1000ppm.

 

[mknauss]

I use a couple trichlor tabs in a floater when we leave in the summer too. Primarily for the acid. Works OK>

CSI is what you are managing. I do the same thing.

 

[Killer95Stang]

Back after 10 days on vacation, so I will update my findings.

A little background, we've had an usually cool summer so far in my part of Socal, so I've been able to manage my TF crystal clear pool with my trusty last legs solar cover and my SWG (IC40 set at 35%), plus a couple additions of MA twice a week (give or take). Since i was planning on being gone for so long, I figured that I needed something that could keep my PH at or around the 7.2 -7.6 level, since my CH is floating at 800ppm. Higher PH that could cause scaling was really my only concern, because the SWCG would manage the chlorine. To prepare for this, I purposely left my CYA level a little lower in anticipation of using the evil Tri-chlor puck to add the extra CL, ACID and CYA I needed. What I didn't prepare for was the heatwave of 90 -100 degree weather we had the day after we left.

So the day I left, I adjusted my SWCG to 40% and I added 4 slow desolving HTH pucks that I purchased in a small bucket from Walmart. I also left the cover off the pool, because I didn't want the pool to be 90+ degrees when we got back.

Of course on our Uber ride on the way back from the airport, I was already thinking about testing the pool water. To my surprise, I had nothing to worry about.

I only tested for CL and PH, because I'm really kinda tired from 10 days with my extended family.

CL = 7
TC = 7.5
CC = 0.5
PH = 7.6
Water temp 84 degrees

Bottom picture shows how much of the undisolved Tri-Chlor tabs were left after the 10 day trip.

 

[mknauss]

Did great!

Could you add the volume of your pool to your signature?

Thank you.