Does the Rainbow 320 Chlorinator work?

Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
I am having some issues with my chlorinator not keeping my chlorine levels up and my pH and CYA and such are at good levels so I have been doing some troubleshooting lately and having to add liquid chlorine and the chlorinator isn't doing its job.

After watching this video I was wondering if you guys think he is right or if he is in fact making a mistake by not keeping the cap off of his chlorinator while the pump is turned on in order to allow the water to fill above the tablets and this would then give him water flow? There are several comments that say that is his problem and he is just doing it wrong. I do allow water to build up with the cap off and pump on before I close the lid so that isnt my issue.
I kind of want to buy a 320c that has the clear plastic so I can see if there is flow in there.

My chlorinator fills with pump on and cap off, it drains when pump is off and cap is off so I am not sure what else I need to check as to why my chlorine levels are not rising with the chlorinator. I run my VS pump at 2500rpms for 8 hours and I have ran it for a full 24 hours to test if that would raise the levels so I would think that would be fast enough to run the water through it. I have the valve on the chlorinator set to 5.
Also my tube is on the bottom of the chlorinator and not on the top like his. Recently I have read that if you use 3" tablets it needs to be on the top but I've seen a few videos of people with it on the bottom and using 3" tablets with no problem.
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,131
Stuart/FL
Mork,

Looks like you joined TFP a while back so I'd assume you know we don't recommend tablets for long-term chlorination due to the eventual build up of CYA that interferes with disinfection. Tablet chlorination only works if you drain part of your pool frequently to keep CYA in range. Also as CYA approached the top of the range significantly more FC is required to properly disinfect. If not, I'd invite you to read through Pool School. Please do feel free to ask any question on this.

Getting back to your video and question, it looks to me that he's got the valve hooked up wrong. The one I have has the valve hooked up to the bottom of the tablet tube not them tap near the top. There is also a fitting inside the chlorinator tee that provides pressure drop sufficient to create flow from the lower fitting tap to the hole on the bottom of the tablet tube. Google "Pentair 320 chlorinator" and you'll see what I mean. They all look like I describe. I have seen the extension kits but I found I had good flow to the lower tap with no modification. My PB installed the chlorinator but I never used it for anything other than holiday travel. I used liquid chlorine per TFP for 5 years this way and worked perfectly. Recently switched to SWG so the chlorinator is even more obsolete now.

I hope this is helpful.

Chris

PS I did get the instructions out and see where they recommend first putting in smaller tablets and if this doesn't work to try the top of the column plug. Clearly from the video there isn't sufficient head and the extension is needed. My guess is that with the extension it would work at the bottom location also and probably better.
 
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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
12,165
Bedford, TX
Mork,

Unless you provide us with a full set of test data from your ColorQ, then we have no way to know what "good levels" are... :mrgreen:

If the chlorinator were bad, then the tablets would not dissolve.. Is that the case?

If not, then the other most likely problem is that your CYA is so high that you can't generate enough chlorine for your pool..

Or you have an algae bloom, even if you can't see it yet, that is consuming your FC faster than you can replace it..

Thanks,

Jim R.
 
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Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
Below are the last few days, not sure why my CYA went from 50 to 71 in just a few days, but I'm hoping it goes down without having to drain water. It did rain REALLY hard here for 2 days so maybe that had something to do with it. I've been testing the water quite often because I am trying to get it under control like I had it in winter but cant seem to get everything stable.

Yesterday I saw like 3 palm sized spots of mustard colored algae and I brushed it off and then again it is back today. It seems to come back in the EXACT same spots when it does show.

21st April
FCL: 2.58
TCL: 2.88
PH: 7.8
ALK: 157
CH: 199
CYA: 71

18th April
FCL: 1.68
TCL: 2.08
PH: 7.8
ALK: 157
CH: 184
CYA: 50

17th April
FCL: 2.74
TCL: 2.03
PH: 7.7
ALK: 163
CH: 211
CYA: 39

16th April
FCL: 2.79
TCL: 2.9
PH: 7.8
ALK: 172
CH: 201
CYA: 52

15th April
FCL: 0.12
TCL: 0.23
PH: 8.0
ALK: 155
CH: 198
CYA: 66
 

Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
Just tested it just now on 22nd April and here are the readings:

FCL: 0.99
TCL: 1.32
PH: 7.9
ALK: 154
CH: 196
CYA: 50

So for a 15,000 gallon pool I should shock FC to 20 with a CYA of 50 going by that chart???? That sounds like a bit much...
I thought I should shock FC to 10 according to instructions on the liquid chlorine bottle?

First I need to put in 18 ounces of muratic acid to get the PH correct though which I will do right now.
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
16,035
Laughlin, NV
So you need to SLAM? 'Shock' is not a process. SLAM is.

And yes, to defeat algae, you need to raise and maintain your FC to 40% of your CYA until you pass the three criteria described in the SLAM article. You need a FAS-DPD test for FC during a SLAM.
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,131
Stuart/FL
Your CYA level won't "go away" Most likely the variations are due to inaccuracy of your test results. As you probably know we recommend the TF 100. Could be you're not completely crushing the tablet or just the variability of the test. CYA will linger for months with very little change. It doesn't degrade from sunlight and reaction with organics. You should look at Pool School and the link below called TFP for Beginners. Also, look at the FC/CYA chart. Your CYA level will continue to rise with the tablets. Each one adds about 2 ppm CYA and you are already above the recommended maximum CYA that TFP recommends. The recommended level is 8-10 ppm FC with that CYA level and an absolute minimum of 5. Below this level your pool is not adequately disinfected. We use liquid chlorine or SWG to chlorinate so the build up of CYA can be avoided. CYA can only be reduced by replacing some of your water.

There are also other changes needed to balance your water chemistry but you should get the proper FC first. TFP has a lot of experts that will talk you through transition to the TFP methodology. Marty is one such expert. and I think he's provided advice as I'm typing. Please feel free to ask any questions. You'll be on TFP autopilot in no time!

Good luck to you!

Chris
 

Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
So will this be an adequate FAS-DPD chlorine test kit: Amazon.com : Taylor K-1515-A Drop Test Kit FAS-DPD Pool Chlorine .75oz 1 Drop = .2 or .5ppm : Swimming Pool Maintenance Kits : Gateway

Everywhere I have read typically says 1-4 FCL and 30-50 CYA but that chart says if I have 50 CYA then I need 4 FCL as a minimum and 6-8 is my target?
My Dolphin S200 says it will not be warrantied if in over 4FCL so why would I maintain 6-8 as a target with 50 CYA?
Every time I go to pool store and test they never say anything about my CYA being too high. For some reason on their sheet they have CYA at 30-200....??

Yea I think my test may have been off when it shows 71 CYA and I think 50 is the more accurate reading.

I'd be a bit worried about equipment if I were to shock with 20 FCL.... I think I will replace some water and get the CYA down before I start this SLAM as I am not comfortable with so much chlorine.
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
16,035
Laughlin, NV
That type of test is the correct one. Sadly, it is very small and you will use it up quickly. I suggest getting FAS/DPD Chlorine & CC's test

The SLAM level FC based on your CYA is far less active chlorine than any public pool with 1 ppm FC with 0 CYA.
Up to you on draining. You can, just be aware there are risks in draining, especially in your area with high water levels.

All of those ranges you state are from chemical companies that do not follow the science. Have you read through Pool School?
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,131
Stuart/FL
So will this be an adequate FAS-DPD chlorine test kit: Amazon.com : Taylor K-1515-A Drop Test Kit FAS-DPD Pool Chlorine .75oz 1 Drop = .2 or .5ppm : Swimming Pool Maintenance Kits : Gateway

Everywhere I have read typically says 1-4 FCL and 30-50 CYA but that chart says if I have 50 CYA then I need 4 FCL as a minimum and 6-8 is my target?
My Dolphin S200 says it will not be warrantied if in over 4FCL so why would I maintain 6-8 as a target with 50 CYA?
Every time I go to pool store and test they never say anything about my CYA being too high. For some reason on their sheet they have CYA at 30-200....??

Yea I think my test may have been off when it shows 71 CYA and I think 50 is the more accurate reading.

I'd be a bit worried about equipment if I were to shock with 20 FCL.... I think I will replace some water and get the CYA down before I start this SLAM as I am not comfortable with so much chlorine.
Mork,

You are asking great questions, keep it up! We can't explain why pool stores don't all understand the relationship between CYA and FC. Some do recognize this and some do not. What we can tell you is there are a lot of pool owners that stumble by this site with pool problems and they are puzzled by this because they have plenty of FC. When they test CYA we find it's sky high. TFP methodology is based on chemistry as documented by water chemistry experts. It is not based on beliefs or hearsay. For decades this relationship was not widely known. Around 2006 several water chemists started to publish the information in industry publications. Click here for an article that sums up the history in more detail. Many pool stores and pool service companies now recognize the proper way to disinfect a pool and do it properly but there are an amazing number that do not. Even the manufacturers of trichlor are now starting to recognize the FC/CYA issue. I don't think there is an intent to deceive by pool stores but I do think there is still a lot of ignorance and lack of training. But there certainly could be a conflict of interest when a pool store can sell you hundreds of $ worth of chemicals in addition to the only thing you really need which is liquid chlorine. We get many people coming to this site that have been "through the mill" with pool store driven solutions and hundreds of $ on chemicals and their pool is still a mess. Properly done a SLAM converts the worst pools into perfect pools within days and using liquid chlorine only... and with the right FC/CYA. Marty has advised owners like you through this process many, many times. Luckily you don't have a green pool yet. But one of the early signs that a problem may be developing is an inability to keep sufficient level of FC.

Please do click on the last link in my signature and read through Pool School for more thorough explanations. Also you can just Google "CYA and FC pool chemistry". You'll find the FC/CYA ratio is now widely documented by respected experts and you'll also see there are still plenty of others that ignore the fundamental issue which is the ratio of FC to CYA. TFP methodology focuses on liquid chlorine or SWG produced FC to disinfect your pool and balance the rest of your pool chemistry to protect your pool surfaces with simple, cheap and widely available chemicals. And very importantly TFP doesn't sell anything so there is never a conflict of interest. We are simply pool enthusiasts that want to help pool owners learn to care for their pool themselves.

I hope this is helpful.

Chris
 
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Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
Yes I have read pool school before but will re-read as clearly there are things I have forgotten in the last few months and this is my first Spring/Summer with a pool.
I guess you can compare oil changes to the same thing as pool chemistry. It is still recommended in 2019 to do an oil change every 3500 or so miles just like they recommend certain chemical levels and I have read many places this is no longer true as oil has come a long way and so have engines so I change my oil every 10k or so miles and have been doing so for about 10 years with no issues.

I see that I need to do a mustard algae shock which at 50 CYA would be 29.4 FC so I am going to drain the pool to get my CYA down.
The mustard agae shock is quite thorough, I don't believe I will be removing lights from niches and replacing lights and such. so lets hope I get rid of it without having to do that. The mustard algae only shows in certain spots and it is always the same spots.

Also going to lower my PH to 7.0 and then raise it back up with aeration to lower the alkalinity from 154 to 60-90 somewhere. Previously I had read that 154 was fine and I saw it in so many places that I ignored it here where it says 60-90.
Once I get my ALK to 60-90, PH to 7.6 or so and CYA in the 30s, and get my test kit I will then begin the SLAM process and see if I cant get this pool under control.

Reading pool school now so I'll come back with any additional questions.
Quick question, if you have CYA of 50 you should keep FC at 6-8. I was told not to swim in FC over 4... I assume if this is not true?
 
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Hootz

Bronze Supporter
Feb 5, 2018
50
Rogers, AR
It is perfectly safe to swim in the FC levels recommended in the CYA/FC chart. That includes SLAM levels.

As per your chlorinator issue these units were not designed with a variable speed pump in mind. If you are running your pump at a low rpm the chlorinator will not provide proper chlorine levels.
 
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Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
Since I have 50 CYA and have never had my chlorine up to 6-8 like I should have, before I SLAM I am going to see how my chemicals work with the proper FC in the pool.
I read THIS and it says that I should expect to replace 2-3ppm of FC daily and I did not know that.... I thought I should only be adding chlorine once a week and maybe twice a week and thats a big reason I thought there was a problem.
 

Hootz

Bronze Supporter
Feb 5, 2018
50
Rogers, AR
Once you get a feel for your pool and know the average use you can reduce your testing to every few days but you will have to add chlorine every day. After starting the TFP method your pool chemistry will get to a point where you can predict the average levels and add chlorine based on those averages. Testing is required every so often to confirm the levels and adjust. When you first start, testing every day for FC, CC and PH will help establish a base. Alk and CH can be tested weekly and adjusted as necessary. CYA does not change very quickly; some test bi-weekly or monthly. If your pool is Gunite you will also need to pay attention to the CSI (calcium saturation)....this level is calculated automatically in the Pool Math app.
 

Morketh

Well-known member
Oct 17, 2018
81
KATY/TX
Cool, I'll have to get used to that because I was enjoying not having to do much in the winter because the chlorinator was doing most of what I would have had to do and costing very little.
I pay $9.98 for 3 gallons of 10% liquid chlorine from Home Depot.
Is that a decent price compared to what you see everyone pay or should I look for cheaper.
I was paying $5 per gallon of 6% clorox bleach which was a bit ridiculous.
 

Hootz

Bronze Supporter
Feb 5, 2018
50
Rogers, AR
That is a decent price. Look at the date code to make sure it has not been sitting on the shelf for a long time. Another option is if you have a pool store or chemical outlet close they may sell bulk chlorine; It is sold in reusable containers to be re-filled.
 

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