Water Chemistry. Need some help.

[Milly]

So just drained and refilled hot tub. Followed the startup procedure from my dealer.

Includes adding Elimate1. ( i assume that is like metal gone )
Then I add Care Free Boost ( A granular chlorine formula that works with in conjunction with ‘Care-Free’ to kill and control bacteria and algae in hot tub water.)
Then I add Care Free (works in conjunction with above )
Then i add Soft ( A granular product that enhances bather comfort, reduces calcium buildup and protects against pH bounce)

After all this is said and done I test PH and CL, Levels are good. Then comes the hard part.

Problem 1: So i have these test strips to test for ALK, and they are never accurate, they are from aquacheck. I dip them, wait 15 seconds and compare to chart. I can never really tell where the ALK is, the color just really does not match any of the chart, if anything it looks to be high. So I decided to go out and buy the aquacheck trutest which actually gives a digital reading. Well that is not any better, I dip strip, flick excess water as per instructions, then read. In the matter of 5 minutes and 5 strips my ALK reading will go from 40-140. So i have no idea if which strip actually is accurate. Having to go to my dealer to get water tested weekly is not an option.

Problem 2: Calcium hardness, I have no way to test this other then to bring my water to my dealer to test, which makes it a pain in the butt.


So basically just wondering why am I having such a hard time with ALK. Is there a decent product out there that can give me some real accurate readings, some kinda Kit?? I just hate it if I have to go to my dealer all the time for water testing. Would much rather to test it at home my self and adjust accordingly.

[SurgTec]

I'm not familiar with the products you've mentioned - but I will offer the benefit of my 'experience' for what it is worth.  I have a Marquis Quest spa - which uses bromine and mineral cartridges in a 'closed' filtration circuit.  I've owned this spa for over 5 years with no problems.

I had previously owned a 'Leisure Bay' - big box store spa - used bromine in a floater and added other 'chemicals' as needed.

What I've learned in years of spa ownership - is "less is more".  I test my spa once a week, I shock once a week, I change out my filters once a month and do a water change / refill every 4 - 5 months.  I don't use ANY extra chemicals beyond the mineral and bromine cartridges and weekly shock treatments.  I use "aquacheck" test strips to monitor my bromine useage.  I adjust the my bromine feeder cartridge open more or less depending on the test reading.

Early on I had trouble with cloudy water and the more "stuff" I added the worse it got.  Letting the circulation / filtration system do its job and not dumping a ton of chemicals in the water is what has ultimately worked best for me.  The water is clear, no smells, no foam and I have minimal maintainence effort.

Just my two cents.

[chem geek]

Same post as in this thread and answered there as well.

[paulsimmons]

You can buy a better liquid test kit- usually the AquaChek Red is adequate for a residential hot tub.  But if you would like to get extremely accurate readings, you could use a test kit that is used in commercial facilities that will test for free and total bromine, pH, acid and base demand, total alkalinity, calcium hardness and cyanuric acid.  Unfortunately, they can be fairly expensive...around $70 or so I believe

[chem geek]

As I noted in the thread I linked to in my post above (where this thread was already answered), the Taylor K-2006 test kit is the best one to get for chlorine as it tests for Free Chlorine (FC), Combined Chlorine (CC), pH, Total Alkalinity (TA), Calcium Hardness (CH) and Cyanuric Acid (CYA).  The chlorine test is drop-based where you count the drops until the sample turns from pink/red to clear.  If you use a 25 ml sample, it is accurate to 0.2 ppm or with a 10 ml sample to 0.5 ppm.  It is around $46 plus shipping from the link I provided -- you don't have to spend $70 for this kit.

Test strips, including AquaChek, are not very good.  You can see a comparison table to see that no test strips check for calcium hardness, only total hardness which includes magnesium so is essentially useless to predict if the water would scale or to know if you have enough CH to prevent foaming.  The accuracy for the other readings is pretty bad as well.