What does red result for phenol test mean?

Dave342357

New member
Jun 28, 2021
1
Central Ca
Hi,

The test sample turns red, not purple or yellow, a color that is not on the little test kit. What does that mean, between purple and yellow, higher then purple, lower then yellow?

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The pool is a metal frame 10'x30" Intex we just bought at the start of this summer, luckily we found one that didn't include the pump as we previously had a blowup version the same size that we kept the pump and hoses from. (Not the tiny pump that came with it, we bought a 1000gph one) And we're right in the middle of San Jaoquin Valley, Ca.

This is my list for startup.

1200g freshwater
6.5oz (3/4c) 8.55% or 9.5oz (1-1/8c) 6% or 13oz (1-1/2c) 4.5% Bleach (FFS this year bleach is 7.5%, you must check every bottle)
1 Cup Borax
1 Tbls Algecide (repeat every 2 weeks)
13 oz CYA 1.6 cups

The PH is always high right out of the tap, a bit darker then the dark purple bar on the kit. I go with 8.5 and use the pool math calculator and bring it down close to 7.5 (matches the lighest purple on the kit) by adding muratic acid.

We keep it covered when not in use to minimize CL loss and keep dirt out. I usually have to add bleach every other day to bump it up from .5 to 2.0
(Which brings up another question, why does the calculator reccomend CL of 4 when my kit says that's too high?)

Between splashing and evaporation I have to add an avg 20g of water a day.

The water looks and feels great after start up and I usually test it each night so I can add chems and let the pump run all night if I need too. We usually vacuum it before each use and the water stays clear if I don't forget to add algicide every 2 weeks.

The PH usually creeps back up as water is replaced but recently the test has come back red instead of purple and I don't know what it means. Is that the color that would be between the purple and yellow or is it off one end of the scale? I'm wondering if I put too much muriatic acid in it last time (2 oz) when it seemd to be turning too purple.

Note: I have a 90 fitting on the water outlet that causes the water to flow in a circle (outlet to daul inlets) when the pump is on. I added it so the water surface is calm and I can see through it while vacuuming. (Vacuum attaches to one of the pump inlets) I do have an aerator fitting I can add to the outlet line though I've never had reason to use it.
 
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I’m not familiar with this particular test kit but algaecide adds metal and that can skew test colors in some types of kits. Chlorine level is based on cya level. Waiting several hours after adding chemicals will give better test results. Soon someone will chime in about what type of testing kits to use. I won’t, cause I’m no expert.
 
The test sample turns red, not purple or yellow, a color that is not on the little test kit. What does that mean, between purple and yellow, higher then purple, lower then yellow?
On the kits that we like to use, yours is a color we have that is closer to amber and being low. No idea where the yellow comes from, or if it’s a factory error. Hopefully someone who knows that kit will chime in. Hang tight.
 
Hey Dave 👋
Glad u found us!
I am not sure what kit you have but if you have stored your kit outside it can bleach out the comparator block. (This happened to my poolmaster kit years ago)
Also your kit is not capable of testing to the level of fc you need which is above 4ppm. An oto test is really more of a “do i have an chlorine at all?” Kinda test as it only tests total chlorine not free chlorine (good stuff) & combined chlorine(bad stuff) separately.
We follow the FC/CYA Levels
If you added 13oz of dry stabilizer to your 1500 gallon pool that’s 65ppm so you round up & chlorinate for 70ppm which is a fc target of 8-10ppm.
Do you have a way to test ta?
If you have high ph water out of the tap you shouldn’t need to add borax - it raises ph& ta.
Also algeacides are on the naughty list, proper chlorination according to the FC/CYA Levelswill keep algae at bay.
Tfp recommended fc levels are based on chlorine’s relationship with cya - the recommendations from your test kit are not. The more cya the less effective your chlorine becomes but without any cya a small amount of chlorine in your pool can be too harsh & the sun will consume it rapidly so there must be a balance.
At this point you either need to get a kit that can test the fc levels you need to use for your cya level as well as give u reliable results for other parameters (the tf100 or Taylor k2006)
or
drain & begin again only putting in 30ppm cya so you can maintain a lower fc that is somewhat measurable by the kit u have.
Heres a guide for temporary small pools you can follow 👇

also have a read of ABCs of Pool Water Chemistry to get a better understanding of all the different parameters.
 
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