Setting up new fill, CH color change

[ryadre]

So have a new test kit arrive today, it's comparable to the Taylor kits apparently (we can't get them here).
When trying to test CH it should change from red to blue. I used the supplied 200ppm test water to confirm it works. When I test (both standard and high tests) my water goes clear instead of blue. I figured because I had no calcium, so I have added 130gm of calcium chloride which should raise CH by 98 using Poolmath. During testing I saw it go clear at 125ppm so I figured it's OK. My pH is low at 6.8 at the moment, would that affect it? My FC is 7.5 and my Cya would be around 14 by now. My TA is 60

 

[Jezza]

I’m assuming your using the Clearchoice kit. If it’s going clear rather than baby blue it doesn’t sound right to me. Have you reviewed the testing instructions to ensure that you are doing your testing correctly?

 

[ryadre]

I’m assuming your using the Clearchoice kit. If it’s going clear rather than baby blue it doesn’t sound right to me. Have you reviewed the testing instructions to ensure that you are doing your testing correctly?

Yes that's the kit. Have done the test quite a few times now. I did the test with the supplied 200ppm water and it went blue, but with my water it is going clear at 100ppm and now 125ppm after I added more calcium. My pH is up to 7.4 now so I do t think that affects it. I did a Google and found some other posts stating the same thing with it going clear

 

[santacruzpool]

Could be a fading endpoint issue - I have that problem with my TF-100 CH tests, so I add a few drops (I add as many as 6) of the R-0012 reagent before the R-0010 and R-0011 - Just remember to keep track of how many R12 you added at the beginning. Also, really really mixing between drops helps - I see lots of tiny pink "floaties" in the water sample after adding the R-0011.

From the Taylor Site:

Beware the Fading Endpoint
Occasionally when testing calcium hardness you may get a purple endpoint instead of blue. This is called a "fading endpoint" and is due to interference from metal ions (most likely copper from algaecides, pipes, or source water). Retest, but prevent the interference by adding five or six drops of hardness reagent to the sample before adding the buffer and indicator. Then proceed as usual. Remember to count the drops of titrant added at the beginning when you calculate the total number of drops required to reach the endpoint.

 

[ryadre]

Thanks mate. For reference I dipped a test strip and the colour appears to be over 100ppm. I think I also read somewhere about adding extra drops.
When you add the extra drops, how does that affect the outcome? Whats the calculation for the reading?

 

[santacruzpool]

When you add the drops ahead of time it will just be your starting point to work from when you get the R-0010 and R-0011 in there. Then once you start adding the R-0012 you start at how ever many you added at the very beginning...

So if you add 4 drops at first - after adding the right amount of R-0010 and R-0011 your first "new" drop of R-0012 will now be 5 - keep counting from there until you get the proper color change to blue (mine is very light blue but obvious blue). It also helps to really swirl a good amount between each drop if you don't have a magnetic-stirrer.

 

[santacruzpool]

Here is the "official" TFP extended test kit instructions for CH:

Extended Test Kit Directions

Extended Test Kit Directions These directions are for use with test kits based on Taylor chemistry, such as the TF-100 from TFTestKits.net, the Taylor K-2006, and the Leslie's Chlorine FAS-DPD Service Test Kit, and also for a few other tests that are commonly recommended here at TFP. Over the...

www.troublefreepool.com

 

[santacruzpool]

If you notice this statement in the above directions: "...changes to something more or less blue" - That of course make things just a little less ambiguous doesn't it!

At least for me mine now turns a nice light sky blue - I do the test with 10ml of water and each drop is 25ppm - since I know I am over 250ppm I often put in 6 or more drops of the R-0012 first and start counting from that starting point after the other two are added.

 

[ryadre]

Thanks a lot. Another question I have is regarding Combined Chlorine.
So my story is that I have been getting a bad rash from this spa that came with our house. I have since used Ahhsome and got a bit of gunk out, and refilled and am doing the dihlor/bleach as per the recommendation here. I will be testing the pool tonight for the first time since cleaning so fingers crossed with my rash!
I tested the CC and the water was very very slight pink tinge to it against a white paper. Then adding one drop (0.5) makes it completely clear. So I guess my combined chorine is at or under 0.5? And I guess as it was only slight tinge of pink it would be relatively low? No one has used the pool since cleaning last weekend, and my FC is staying up at 7.5 over two days (started at 10, then was adding 4gm dichlor each night using test strips as my kit hadnt arrived)

 

[santacruzpool]

<.5 CC is fine - which is exactly what you have tested. Combined Chlorine can and will build up a bit in the spa if it is kept closed for extended periods of time (but, but, isn't that how we keep it warm). Opening it for 30 minutes to an hour with the jets running at least a few times a week, especially when in sunlight, can help clear out any excess CC. You will also get some CC from organics, especially if you have a higher bather load - think sweat, skin, dirt and any other nasties...

I found that my second fill was cleaner than even my first fill - this was after doing Ahhsome twice. My CC levels went down after my second fill as well.

You can also shock the water for a day or more with a higher amount of FC if your CC's climb a bit too high to help burn them off. There are other options like MPS but I have never used that. If the CC's do get above 1-2 and stay there, then for me that would be a good time to look at doing a quick Ahhome treatment, drain the water and do a new fill. Hopefully that won't be for a while...

 

[ryadre]

Great, thanks mate. Yea there will be five of us probably using it a few times a week, for the next month or two until the weather starts warming up. Its in a shady part of the property with tree around so I dont like leaving it open for too long - leaves etc.
We oringinally filled it and cleaned with a product called swirl awayy and then drained. Then we used it for maybe a month and only I was getting rashes from it, so we bought ahhsome, cleaned away the gunk, left overnight and then ran again (also added some more ahhsome) and any foam looked clear, so drained and refilled with filtered town water last weekend and started adding dichlor.

 

[santacruzpool]

Good luck, sounds like you are doing good - hopefully the new water agrees with you.

Make sure to keep a good eye on the FC levels - If I am the only one using my tub it is pretty easy to figure out how much chlorine will be needed, but adding extra people adds more complexity. When my son or wife use the tub the amount of chlorine needed is much higher. My first month or two of having the hot tub I would check the FC every day, and despite adding what I thought was the right amount after it was used, a few times the FC would be close to Zero the next day...I ended up with a little infection irritation after one of those mistakes, so I understand where you are coming from.

Keep it clean and keep the FC above the minimum at all times and you will be good.

I also found out that making my son shower before he gets in is a good way to keep things much cleaner - I do the same now. My other tip is to watch out for foam from swimsuits that come out of the laundry - or when someone doesn't rinse off well enough in the shower (cough cough - my son) - I get a bit of foaming if I don't rinse my swimsuit after my wife puts it through the laundry, and when my 10 year old son jumps in fresh out of the shower with soap still on him...grrrrr.

 

[ryadre]

Thanks, we all five of us had a spa and fc went from 7.5 to 1.5, so I guess we should always start with a higher 6 or 7 fc so we don't get to 0? We thought about the foaming as well and pre rinsed our swimsuits in clean water and won't be washing them in detergent after every swim
Edit. And my recent test this morning the ch went blue like its supposed to at 125ppm