Dosing Pump for Vacation Use: How Much Daily Chlorine?

[EuphoriaOwner]

I bought this little pump to add liquid chlorine to my hot tub during times when I will be away from our house on vacation.

BRS 2 Part Doser - 1.1 mL per minute

Why does BRS recommend this? The BRS 1.1 mL dosing pump is a very cost-effective yet long lasting stand-alone dosing pump perfect for trace elements and 2 part. By hooking the pump up to a simple timer or aquarium controller they can be one of the most inexpensive ways to get into an automated...

www.bulkreefsupply.com

We just bought a used fifth-wheel and will be taking trips of anywhere between one week and six weeks. So I wanted a simple solution to keep the water clear while we are gone without having to bother a friend to stop by and add chlorine. We have storage steps in front of the spa. I will locate the pump and chlorine jug inside the storage steps. The pump will run on a timer. I tested the pump/timer set-up yesterday and it moved 2.7 ounces of fluid via slow drip in one hour of run time.

I am trying to determine a good level of chlorine to add daily while we are away to keep the chlorine levels adequate to maintain clear water. Obviously, I want to err on the side of too much vs. too little.

We use the hot tub daily -- just me in the morning for 15-20 minutes then usually my wife and I in the evening for 15-20 minutes. I add about 2 ounces after my morning soak and about 3 ounces after the evening soak. This has worked great for years.

I am just not sure how much lower the chlorine demand goes when a tub is not in use. I was thinking I could run the pump for 30 minutes per day when we are away, which would put in about 1.35 ounces of chlorine per day. Does that sound about right or should I bump it up a bit just to be safe?

 

[Newdude]

I am just not sure how much lower the chlorine demand goes when a tub is not in use

So make believe you went away and stay out of the tub for several days. Get your baseline non use FC demand from that and adjust after the first trip if necessary. With the hot tub covered and unused the demand should be pretty consistent.

 

[Mdragger88]

 

[Cousinvinny]

I like this iea. I didn't see if it was mentioned but is this pump compatible with chlorine?

 

[EuphoriaOwner]

Here is an old thread from another forum that inspired me to pursue this idea: Liquid chlorine (bleach) slow dispenser. The thread goes a bunch of different directions, but as you can read near the end, a few of the hot tub owners had purchased the same pump that I bought and using it for chlorine dosing with success and no issues with chlorine damage to the pump or its tubing. So this is not a novel idea on my part, just piggy-backing on what these others have already done.

I did some of my own research on pumps. You can find much cheaper pumps on Amazon (as low as $15) if you want to inexpensively experiment with this idea. The reviews on the cheap pumps indicate a higher failure rate for the pumps. I wanted something that I could rely on and that would hopefully last for years. So I went the BRS pump that I linked.

My pump is now rigged up on our tub. I am going to experiment with the daily dose while we are still using the tub. Then I will make a guess on the extent to cut back the dose when we leave for vacation next week. As suggested above, I could just stop using the tub for a few days to get a more precise vacation dose estimate, but I don't want to not use the tub for two days.

I will keep the forum posted as to how this works when I get back from our one-week vacation.

 

[Cousinvinny]

Looking forward to seeing your results.

 

[EuphoriaOwner]

Back from vacation. I set up the dosing pump timer to run from 10 to 10:15 am and from 10 to 10:15 pm while we were away. My initial test of the pump showed it pumped 2.7 ounces per hour (see post above). So with two, 15-minute run sessions I was adding about 1.35 ounces of liquid chlorine per day while we were away. I forgot to turn down the water temperature. So the water was at 101 degrees while we were gone for 8 days. The chlorine level was a bit high when we got home, but I was planning on erring on the side of too much chlorine vs. too little. Next time we go away I will cut down to about 1 ounce per day and see how that works.

Overall, I am pleased with the set-up and not having to bother a friend or neighbor to come and check on the spa and add chlorine. Now I am trying to figure out how to get a 110 volt plug out at the spa so that I can do away with the extension cord that I ran out to the spa while we were on vacation. I would like to use the dosing pump even while we are at home as it is so convenient.