Just Got My Taylor Kit..and Some Numbers

[markley]

So I just got my Taylor kit in the mail. I ordered online from Amato (thanks for the recommendation; easy transaction and speedy delivery). Anyway, I just got some numbers and just curious if I need to tweak anything.

Here they are:

FC = 0.4 ppm

CC = 0.6 ppm

pH = 7.8

TA = 80-90 ppm

Calcium Hardness = 150 ppm

CYA = <30ppm (filled all the way up and dot finally disappeared)

I guess I should state that I am using the Nature2 system, and adding non-chlorine shock (MPS) after each soak and dichlor once a week. I just started with this system so still getting used to it.

Any comments/suggestions would be greatly appreciated!!

[chem geek]

Since you are mostly using Nature2 with MPS, you need to be measuring the MPS level, probably with an MPS test strip. The chlorine levels won't be particularly relevant and the CC will be interfered with by MPS. I suppose that theoretically you could use the CC level for MPS, especially if you get the Taylor K-2042 MPS interference remover (which, as part of the test, will give you separate numbers for MPS and true CC). With your system, you mostly should be measuring MPS and don't care much about the chlorine level. If I assume your CC is all from MPS, then that's 0.6 ppm in chlorine units and might be 1.0 ppm if some or all of the FC is also falsely measuring MPS (in units based on weight of non-chlorine shock product, this is multiplied by around 4.8 so would be 2.9 ppm). The Nature2 owner's manual has you add an amount of non-chlorine shock that is 1 tablespoon per 250 gallons which is roughly equivalent to around 4 ppm in chlorine units so I suspect that you should be having the MPS in your spa such that your typical CC reading is closer to 4 ppm -- but get an MPS test strip to be sure since I don't know what the setpoints of their "Low, Good, High" levels.

The pH is a little high, but shold drop along with TA over time as you continue to use MPS since it is acidic. You don't need to worry about the CYA level since it won't rise very fast since you are only adding Dichlor once a week.

With the Nature2 and MPS approach, it's probably OK to get the less expensive test such as the Taylor K-1005 or Taylor K-2005 as these at least test for pH, TA and CH which is what you mostly need for Nature2 and MPS assuming you also have MPS test strips. At least if you decide to every go with the Dichlor-then-Bleach method, you've got the right test kit for that.

[markley]

Thanks for the reply!! I do have MPS test strips. When I checked with the strips it did not appear to register any MPS, well it was on the low side. Should the MPS level always register in the ideal range? I usually add 1-2 tbsp (after each use; which is about every other night). To maintain the MPS it seems as though I may have to add it every day. If thats the case I may have to switch to the dichlor-bleach method once i use up all my MPS, as this could get expensive.

Thanks again!! Much appreciated

[chem geek]

In order to have proper sanitation, you don't want the MPS to get too low at any time. It's probably similar to chlorine where you don't want it to get to zero, but should probably be at least 1 ppm (chlorine equivalent) at all times. Nature2's instructions would say it should be at 4 ppm which is probably the "Good" range of the test strip and that it should be this way before your soak and then add enough afterwards as well.

Roughly speaking, you should be adding around 7 teaspoons (2-1/3 tablespoons) of 43% MPS for every person-hour of soaking. Note that some brands have less of the active ingredient which is "potassium monopersulfate" aka "potassium peroxymonosulfate" -- SpaGuard Spa Shock, for example, is only 31% MPS so you would need nearly 10 teaspoons (3-1/3 tablespoons) of this product per person-hour. If it's just you soaking and you aren't soaking for more than 30 minutes or so, then it does sound like you are using the right amount, but it's on the edge and really not quite enough. You could try increasing the dosage to see if you can get to registering a "Good" level or the edge of "Good" to "Low" before the next soak. You probably won't need to add it every night, but the dosage will be higher regardless, and yes that is more expensive. That's one main advantage to the Dichlor-then-bleach method -- it's probably the least expensive approach for methods which are sanitary.