I'm trying to find out why new test strips register no free chlorine, but my fas dpd drop test shows 4ppm free chlorine and zero combined chlorine.
Can the fas dpd test have a false positive result? I even took a small sample and added bleach to it and them the strip showed free chlorine? Last year I had high cya above 100 but it was gone upon opening.
FC 4, cc 0, ta 250, ch 250, cya 30. Thanks for any help you can offer. No one can seem to answer this question.
Thanks for the question Erick
Yes, DPD drops can sometimes give a false positive, but on the whole, they're much better than test strips.
Drops can get old. I believe Taylor recommends replacing them after 1 year.
Be sure you're doing the tests correctly and have fresh reagents. Strips will give a range for the chems but the DPD kit will give you the actual numbers when done correctly.
On my YouTube channel I walk through each test in detail, from how to swirl and hold the vial to the amount of drops to use. Here's the video for the chlorine:
I hope you can help me. I have a 40 000 litre fibreglass salt water pool and I test the water regularly with a 4 in 1 pink test kit.
I use DPD tablets for the chlorine and drops for ph. When I tested the water myself at home today the chlorine comes up in the ideal range at 1.5 and the ph has also has come up in the ideal range at between 7.4 and 7.6 when I took the water to the pool shop to be tested straight after I had tested at home they said that the chlorine was low and I needed to add chlorine immediately as well as needing to add acid as the ph was too high.
There is a high level of phosphate in the pool at the moment as there is a lot of building going on in our estate. I understand that the phosphates eat up the chlorine but I don't understand why the test kit is coming up on the ideal range.
Also It was not my normal pool shop as they were closed. I am confused and concerned that I have been relying on my test kit and it has been incorrect. Can you please shed some light on what might be happening here.
Thanks for the question Ange
First thing I would encourage you to do is get the Taylor K-2006 test kit. It's the most accurate. Try your local pool store and if they don't have or cannot order it you can try Amazon or eBay. I've made YouTube videos on exactly how to use it to get the best readings. Other test kits are alright but if you want the best results you need the K-2006 kit.
Chlorine's range is 2 - 4ppm. You may want to add enough to bring it up to 4ppm. You're into Summer now so you want to keep the chlorine level correct. Also check the CYA and be sure that's in the 30 - 50ppm range.
"High" for the pH is relative. The range is 7.2 - 7.8. I'd get another opinion on the pH if you can. If 2 out of 3 are 8.0 or higher then put some acid in to drop the pH. If 2 out of 3 say the pH is fine then leave it.
Next is the phosphate issue. It's a myth that phosphates eat up chlorine. I've made a YouTube video on that as well and you can find it here:
Basically it's this. Phosphates and nitrates are food for algae. Chlorine kills the algae and organic matter in the pool. Algae is always in the pool but by keeping enough chlorine in the pool (2 - 4ppm) you kill the algae faster than it can reproduce. That's what you want to accomplish. It's a race to kill the algae faster than it reproduces. Phosphates are fine to swim in so if there's no algae (which is what you want) then the phosphate level is virtually meaningless.
Only in extreme circumstances would you need to use a phosphate remover such as an entire bag of fertilizer is dumped into the pool.
Concern and confusion manifest themselves when we don't have the right information. There's nothing wrong with you, it's just you need the right info.
If you watch the video on my home page you'll see that I cleared up a cloudy pool in a couple of days for a few dollars. There are people who spend weeks and hundreds of $$ clearing up a similar pool. I'm not any better than they are and certainly not more intelligent (just listen to me lol), I just have the right info. and use it correctly.
The OTO test kit will indicate a high chlorine level, but it won't tell you how high or what part of it is Free Chlorine, only Total Chorine.
An OTO chlorine test will go from yellow to amber to orange to red as chlorine gets very high.
With the FAS-DPD K-2006 chlorine test, you can measure Free Chlorine (FC) and Combined Chlorine (CC) separately and accurately.
If your OTO chlorine test is red that would indicate a high level of chlorine, but again, I can't tell how high it is.
I'd like to have your complete chemical readings:
Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper).
It makes troubleshooting much easier and the process of clearing up your pool will go much faster. You can get this done at your local pool store. If there's anything else wrong it can be fixed quickly and easily.
To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Pool Water Testing Kits" category.
Check back to this post for updates or answers.
If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.
When I turn on my portable spa--the water turns almost milk white with very small bubbles in the water. What causes these bubbles?
I think my alkalinity is high. What do I use to bring it back down.
Would I be better off draining the spa and refilling it. The spa holds almost 500 gallons.
First, I'd like to have your complete chemical readings:
Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper). It makes troubleshooting much easier and the process of clearing up your hot tub will go much faster.
You can get this done at your local pool store.
Without these numbers I'm just guessing at what the problem is.
"High" alkalinity is a relative term that means different things to different people. I can't tell you if the alkalinity needs to be adjusted because I don't know what it is.
But, if you want to bring it down, you'll use muriatic acid.
For excessive foaming, bubbles and milky-white water, it could be a few things:
- Contaminates (body oils, make-up) and/or soap residue - Buildup in the plumbing system - Low calcium water hardness - Crack in the plumbing that allows air into the system - Filter/pump lid not seated correctly or bad/broken O-ring on lid - Water out of balance and/or old water
Be sure you take a hot soapy shower and rinse very well before entering the spa. Very soft fill water may make the foaming worse.
Get back to me with the chemical numbers and I'm sure I can help. Hopefully you won't need to drain your spa.
If the calcium level is low, you can raise it to 150-200 PPM. This will help reduce the foaming.
To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Hot Tub/Spa Questions" category.
After applying 5 drops of chlorine test solution to my pool sample in the test kit - it turns red, then slowly drops red globules to the bottom. The actual liquid color is light green. After a while, all the red precipitate is at the bottom of the tube.. The chlorine color looks OK, compared to the test colors s
Thanks for the question David
I would assume you're using the yellow OTO kit, is that right? A red color would indicate high levels of chlorine. It's impossible to say with any degree of certainty what the number is because the OTO kit gives ranges and pretty much tops out at around 5ppm. Your FC could be 6ppm or 60ppm.
I would ask the age of the drops? Are they fresh or older? Is this the first time it happened with this bottle? Did this suddenly happen with this dropper, even after multiple times of using it?
If you have a local pool store you can take a sample of water to them for analysis and see what happens. Unfortunately there's no clear cut answer to this without a little more detail.
The confusing part is the question says the color of the sample water turns red which indicates high chlorine, then it says the chlorine color looks OK compared to the test colors.
It would help if I had a bit more detail. Thanks.
If you feel your situation is more complex than this, I do phone consultations for a donation of your choice. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias.