Best way to use an OTO kit

[prh129]

I bought a similar kit to hold me over until Ben's kit arrived at it worked just fine.

As far as diluting your sample, the more you dilute, the less accurate it gets so if you are within the range of the tester, I wouldn't dilute it. If you're staying around 3 ppm with a CYA level of 30 or under you should be fine.

Peter

[waterbear]

OTO only tests TC. It will not give you any kind of accurate reading for your FC, actually some of the test strips might do a better job at this than trying to get a FC reading with OTO (and I do NOT recommend test strips!)

[Rangeball]

OTO only tests TC. It will not give you any kind of accurate reading for your FC

I emailed the kit manufacturer asking if their kit did in fact test for FC and TC, as they claimed, and if they were separate tests. Got this response-

It is not a separate test.

For a free chlorine reading, within 2-3 seconds after putting in the oto drops, compare the color in tube.

For a combined chlorine reading, wait 1-2 minutes after putting in the oto drops and again compare the color in the tube.

True or false?

My color never changes no matter how long I read it. Going by this, I have no CC.

[mas985]

I have used this method before on my spa. I believe that the second part after 1-2 minutes is really measuring TC and not CC. To get CC then you must CC = TC - FC. With a high CC, you will notice the solution getting darker over time. However, you generally cannot measure a CC of < 1 ppm since it is difficult to tell the difference in color. Even at high levels you do not get a very accurate reading. But then again all that you really want to know is that your CC level is bad and your pool needs a shock.

[jrv331]

I was using the Poolmaster Kit for the past two years before finding this forum. Thought it was great UNTIL I got a Taylor kit that had the red vial markings. Being new I tried the FC/TC tests with both kits(being anal)several times - each time it was hard to read with the yellow Poolmaster vial but easy with teh red Taylor vial. Short answer to your question - the Poolnmaster never gave a FC reading despite their instructions.

JOhn

[waterbear]

I emailed the kit manufacturer asking if their kit did in fact test for FC and TC, as they claimed, and if they were separate tests. Got this response-



True or false?

My color never changes no matter how long I read it. Going by this, I have no CC.

This will only work if you have a LOT of CC in the water. It is really not useful at all. If you have enough CC to show with this method of OTO testing you will already know it by the strong chlorine smell and the burning eyes. I stand by my statement that OTO only tests TC! You cannot accurately get a FC reading with it. This is why most health departments ( or is it all now?) only allow DPD or FAS-DPD testing of commercial pools.