Pool testing device - digital preferred - advice needed

[mhca]

Hi troublefreepool

This will require a little bit long intro.

I came across your forum in the search for pool testers.
We have a "public pool" in the sense that we share it 10 apartments, and we are therefore required to measure our pool twice a day and have uannounced measurements by a professional company made approximately every month.

We expect to be 3-4 different people doing the tests, and the general opinion was that we would definitely prefer something digital. However we are also interested in the most userfriendly procedure which isn't too time-consuming.

We have just had installed (1 week ago) an Autodos M2 system which measures and controls the pH and chlorine levels. pH is adjusted with sulfuric acid added automatically as it goes off from the set-point (currently 7.25). Chlorine is added with a Pentair Intellichlor IC40 SWG, when CL level is below the setpoint.

We have until now managed checking the pH and free chlorine levels with a CheckIt Trutest digital strip tester. Browsing the internet, it seems that it is considered useless and very inaccurate. To us it has however seemed very quick and convenient to use.
Now we however need something a bit more accurate for daily measurements which can also measure total chlorine. Also our Autodos system's chlorine levels must be calibrated regularly.


I have seen that many here are fond of TF100 test kits and Taylor K-2006. But since we generally wish to find a digital solution, I would prefer if we could find something that suits that purpose. Also I live in Denmark / Europe and therefore doesn't have the same items available as you.

The testers I have stumpled upon are:

LaMotte ColorQ Pro 7 - this seemed like it received positive comments, although many users also experienced their measurements to be inconsistens or inaccurate compared to TF100 tests.
This will cost us approximately 2200 DKR. incl. reagents - appr. $360.
It seems OK efficient compared to other photometers.
http://www.eseasongear.com/copro7mekila.html

Lovibond Scuba CL/pH/CY small handheld device also requiring powder pills.
Will cost us approximately 6-700 DKR - approximately $100-120.
http://www.ukspastore.co.uk/acatalog/Lo ... ester.html


Lovibond MD200 Checkit Direct
I have seen a YouTube video of this and it seems simple, although not very efficient to do measurements with. Also this is rather expensive even though we may get a good price from our distributor.
I estimate the cost to be approximately 2-2500 DKR - appr. $400.


Are you familiar with any of the Lovibonds? Or can you recommend anything similar for easy, daily measurements?
If we choose such a solution, is it generally recommended to go for liquid reagents or tablets?

Thanks in advance!

Best regards, Martin from Denmark

 

[JasonLion]

None of the digital testers, even the expensive ones, are as good as the FAS-DPD chlorine test for measuring FC and CC levels.

Liquid reagents are slightly better, as there is never any question of making sure the tablet fully dissolves, but the tablets/powders can work well as long as you make sure they dissolve.

Of the kits easily available in the EU, Palintest seems to be the best.

 

[Stuamurr]

Lovibond do a cheap alternative comparator called a "Lovibond Checkit" that can be used when not at shock levels (upto 4ppm), they also have photometers, namely the Lovibond Poolcontrol/MD100/MD200, which you will see at 9 out of 10 Council Pools and Envirnomental Health Departments, it really is the leader, certainly in the UK for water testing, as for Palintest, they are also very good, but tend to me more expensive, if you want digital I would certainly recommend a Lovibond or Palintest Photometer, that said with 10 people contributing equally the price for a comprehensive MD200 6 in 1 photometer would be £37.70 each - no bad! that would be thes easiest device to train everyone in the block to use, you could then add for your Plant Operator to use the Palintest FAS-DPD kit for superchlorination purposes, which looks like working out around another £6 each.

Photometers generally are fine upto 10ppm chlorine, after which you would require a FAS-DPD Drop Kit, I contacted Palintest in Newcastle-Upon-Tyne and their response was the kit would cost SP300 - £33.40 or SP400 - £36.20 with a minimum £50 order value + postage & VAT, so I guess you could order enough re-agent etc for spares to take you over the £50 order value.

Have a look at this website, which supplies a lot of Local Authorities in the UK with the equipment etc.
http://www.leisureteq.co.uk/water%20testing.html

Stuart

 

[mhca]

Thanks to both Stuart and Jason for quick answers.

To Jason:
Yeah, the recommendation of FAS DPD is also what I have seen across this forum. I just browsed it a bit and realised that the nice part of it is that it doesn't require evaluating shades of pink, which we wanted to avoid.
Also, I guess a test kit could be bought cheaply, although I haven't found any shops in DK from a quick search.

To Stuart:
Nice to hear that Lovibond is generally recommendable.
The reason I stumbled upon the Lovibond Scuba and the Lovibond MD200 (3 in 1) is that we have a direct contact to the primary pool distributor in Denmark from which we can maybe get 40-55% discount on their official prices. Based on 50% discount that would bring the two to
$290 for Lovibond MD200 3in1
$85 for the Lovibond Scuba

I like the concept of the Scuba. Seems very simple as everything is mixed in the device itself. I was thinking that this device could probably be combined with regular FAS DPD tests to confirm the Scuba measurement results. We do have automatic adjustment of chlorine and pH, so I hope to see pretty stable levels due to that.

The MD200 also looks nice but requires a bit more finesse and more careful handling it seems. I guess that it is more precise though.


A general comment:
Similar to the Lovibond Scuba, I found a device called eXact Micro10, which also seems simple and efficient to operate and measure with
http://www.sensafe.com/micro10/

I hope that if we find out our values are pretty stable, we can suffice with doing extensive tests everyday and just use simple Checkit tests daily with extensive tests weekly. We do however need some tools to test with decent accuracy.

BR, Martin

 

[Stuamurr]

If you do go for a photometer get a 6 in 1 rather as 3 in 1, the price difference is so low when your spending that much anyway on a really good piece of kit. Ive always used Lovibond MD200's in authority pools or when the Envirnomental Health Officer is visiting and they really are worth the extra, being far simpler to use, and indeed train others to use. A small workstation is best for testing in the plant room, that way your not carrying a £300 piece of kit around.

Stuart

 

[mhca]

Thanks for that recommendation. We'll definately consider the 6in1, which seems to cost appr. 15% more, in case we go for the Lovibond MD200.

I presented my neighbours to the photometers included here.
They were very interested in the eXact Micro 10 concept.
I haven't been able to find any reviews of it, and the only mention of it here on the forum was answered by Jason. Jason found its range (was maybe referring to Micro 7) to be very narrow and that conditions would often be outside of those.

Do any of you have anything to say about the eXact Micro 10?

Generally we would of course prefer precision, but if we are only lacking precision when outside our required range, I think we can live with that.
Our required range is
pH: 7.0-7.6
FC: 1.0-2.0
CC: <0.5

So if we are above those values we would need to consider the pool closed (at least officially) and we are less dependent on very accurate measurements.

 

[frogabog]

Do you happen to know the water's CYA level?

 

[mhca]

Do you happen to know the water's CYA level?

No, we have actually never tested for the CYA level.
In my search for pool testers, I have taken note of the fact that CYA seems to be a pretty standard measurement. And I also remember reading that it could be important with regards to salt water generators.

Are you thinking of anything specific which is important to have in mind?


Update/EDIT:
I just made a quick search and found this Free chlorine vs CYA chart:
pool-school/chlorine_cya_chart_shock

Based on these, it seems that a target of 1.0-2.0 free chlorine is very low compared to the minimum FC of 3 and target of 4.
Those values are dictated by our environmental ministry in Denmark.

 

[frogabog]

Yes, I was about to refer to this CYA/Chlorine relation.

That minimum you refer to of 3ppm is associated with a pool that has 30-40ppm CYA. The target high for such a pool is actually 7ppm. Depending on your actual CYA level (outdoor pool, correct?) the recommended levels would change.

I couldn't say about your local regulations or how you might deal with them but to properly santitize a pool, FC needs to be a minimum of 10% of the CYA level. I you've ever used tablet chlorine (trichlor) or powdered shock (dichlor) there's a chance the pool is well saturated with CYA already. 30-40ppm is on average a good level to keep CYA at. I think in your location, unless it's sunny hot and dry in the summer 30-40ppm is a good value for you to keep in mind.

Take a stroll through Pool School, and you'll have a better understanding of the CYA/Chlorine relationship. There may be someone here who knows more about how it relates to your pool and the Environmental Ministry guidelines.

 

[mhca]

Thanks frogabog.
I have become aware that there is a lot more to pool care than just pH and free chlorine and THM values.

It seems to me that both TDS and CYA will build up and require the pool to be emptied or half-drained. I guess I will be shocked by our levels as we only have part-drain for winter preparation, else only water loss from evaporation (doesn't help for that) and from backwash. Water is added through rain and fresh water.


I will definately keep in mind that it can be valuable to be able to monitor more than just pH and chlorine.
We just have to find a pool tester, which we feel can suit our purpose.

 

[Stuamurr]

A pool that size backwashing should be sufficient to to give a constant replenishment of water, frogabog is correct though, you need to know your CYA level so you can have the correct chlorine residual.

Chlorine needs to be at a minimum 10% of the CYA level, so 50 CYA ~ =>5ppm Chlorine

You can definately get away with quite a low CYA to add just a smidge of stabilisation, given our rather inclement weather tendancies for now

Stuart

 

[GreatCanadian]

.....to properly santitize a pool, FC needs to be a minimum of 10% of the CYA level....

I've seen this 10% show up many times on this board, but unless I am reading the Chlorin/CYA chart and Pool Calculator incorrectly, the 10% does not match with either of these. For example, if you use a CYA level of 60, Pool Calculator and Chlorine/CYA chart show a minimum of 3 ppm for an SWG pool, and 5 for a bleach pool. Neither of these is 10% of the CYA level. Is the 10% just "a safe number"? Or am I reading the chart and Pool Calculator wrong. Thanks.

GC

 

[Stuamurr]

CYA relation to sanitiser level is not a universally accepted science, the only part which is wholly accepted is that CYA slows down the ability of chlorine to do its job, for example if it takes an indoor community pool with no stabiliser present 0.5seconds to kill 99.9% of a bacteria, with 3ppm chlorine it would take the same pool upto 4minutes to achieve that kill rate rate with a CYA residual around the 40ppm level (working from my pool plant course memory here!) if I remember correctly "chlorine lock" that is a point where chlorine stops working because of the CYA level is a myth, and only applies to the CC/FC ratio, in fact the more I remember about it more I remember that the Aussies are the ones that knew what they were doing with CYA and Hypochlorite long before anyone else - which is hardly surprising given that their national sport is swimming.

The argument became I believe that CYA although slowing down the ability of chlorine at low residuals 0.1-1ppm did not stop it and that a normal chlorine residual of 1-3ppm would work sufficiently well in a stabilised pool with a 30-50ppm residual of CYA.

It would be a good idea therefore to check your own countries guidance on the use of CYA and chlorine ratio, from memory in the UK its 25-30ppm and no adjustment to chlorine levels (1-3 ppm) lower CYA = unstable chlorine, higher levels = chlorine inefficiency.

Basically do some research and follow your own countries codes, I doubt they will be much different than the UK's, as you have a community pool you will need to follow your own countries regs though.

Stuart

 

[JasonLion]

CYA relation to sanitiser level is not a universally accepted science

The science is universally accepted. It is the rules/regulations that have not kept up with the science. Some of that is simply because it takes 50+ years for law to catch up with science, and some of that is because a few of the chemical companies have spent a lot of money lobbying to obscure the truth.

If your region regulates the FC levels you can use, you have to adjust the CYA level so you can still maintain an appropriate FC/CYA ratio. If you fail to do so, there will be problems.

 

[Stuamurr]

Hi Jason, the Chlorine Lock claim for CYA is what I refer to in stating that the science is not universally accepted, which it certainly is not in Europe, or by the looks of things in Australasia, as this article claims:

http://www.easypools.com.au/pool-mainte ... lockq-myth

This is certainly what I was taught when I did my last NPPOC here in the UK, which follows the science whilst ensuring that the rules for commercial pools are still adhered to

Regards
Stuart

 

[woodsage]

I've been using the Palin Pooltest 9 for a few years and I am very pleased. The other test kits were too subjective for me and especially measuring CYA.

 

[loop_pea]

Update/EDIT:
I just made a quick search and found this Free chlorine vs CYA chart:
pool-school/chlorine_cya_chart_shock

Based on these, it seems that a target of 1.0-2.0 free chlorine is very low compared to the minimum FC of 3 and target of 4.
Those values are dictated by our environmental ministry in Denmark.

You should check your country's regulations carefully. In the UK there are two recommended ranges - one for indoor pools not using CYA and another for outdoor pools with CYA. For a pool with CYA, we are advised to run it between 2.5 and 5ppm FC. We cannot open the pool if the FC is less than 2.5, but there is more leeway at the top end of the range - we don't have to close it until the FC is over 10ppm.

I had a look on google, and it seems that the legislation in Denmark gives different recommended FC levels depending on the size of the pool (!). Assuming I found the right source of information (executive order BEK no. 288 from 14/04/2005), it gives the maximum FC as 5ppm for indoor swimming pools of 25m in length or less. The reference to indoor swimming pools suggests that there might be another set of requirements for outdoor pools. It could be worth investigating.

 

[mhca]

I've been using the Palin Pooltest 9 for a few years and I am very pleased. The other test kits were too subjective for me and especially measuring CYA.

Thanks for that input. I'll check it out.
I do however think that it is a bit more expensive than the others. Particularly because our distributor probably cannot offer us this with a discount.

You should check your country's regulations carefully. In the UK there are two recommended ranges - one for indoor pools not using CYA and another for outdoor pools with CYA. For a pool with CYA, we are advised to run it between 2.5 and 5ppm FC. We cannot open the pool if the FC is less than 2.5, but there is more leeway at the top end of the range - we don't have to close it until the FC is over 10ppm.

I had a look on google, and it seems that the legislation in Denmark gives different recommended FC levels depending on the size of the pool (!). Assuming I found the right source of information (executive order BEK no. 288 from 14/04/2005), it gives the maximum FC as 5ppm for indoor swimming pools of 25m in length or less. The reference to indoor swimming pools suggests that there might be another set of requirements for outdoor pools. It could be worth investigating.

I'm amazed that you found that information. However, the 288 is not current/valid anymore. We had a Bek 458, which we were looking at until a month ago, where it was replaced by Bek 623 from 13/06/2012. Don't know if you can read the Danish here, but you may get the values: https://www.retsinformation.dk/Forms/R0 ... 42195#Bil1

For indoor pools the FC limits are 0.4-1.5 (I'm amazed that they can sanitize at those levels if a lot of people are bathing). For outdoor pools as ours it is 1.0-2.0. CC is <0.5.
I have been very much aware of all the rules because we have been struggling/fighting with the authorities about our pool and approval of this new upgrade for more than 8 months.

I'll see how it goes with the sanitizing. I think we can manage to keep it clean using 1.0-2.0, but I would prefer to have more "room" to play in with a larger interval. However, with the Autodos M2 system, we may be able to achieve rather stable values, once we've gained enough experience with it and are able to properly calibrate the chlorine electrode and the pH.

BR, Martin

 

[frogabog]

FWIW, I do think if you all tried the FAS-DPD test that you'd really like it. It's not hard to do, and while not digital it's very precise and accurate. Not to mention, come on... it's fun.

We're all adults here, but I dare anyone to say it's not fun scooping the powder, it turns the water pink, and then you drop the reagent in till it's clear. 3 drops, is 1.5ppm. Add 5 drops of the DPD reagent, is it pink? at all? hmmm... maybe a little. Drop in the other reagent, yep, that turned it clear. ok. .5ppm CC. All is well. That's not a chore IMO and the results are clear as day. it's a matter of pink, or no pink.

pH matching is a little harder, but the truth is that it gets easier the more you do it. Test for pH 10 days in a row and you'll feel much better about judging the colors.

I actually prefer the larger pH color blocks and the reagent matched for the larger volume sample. I suspect it's more a matter of the degrees the large blocks read at and the more precise ranges between colors that make it easier. The block I'm referring to would use 44ml of water (Taylor). Sometimes an OTO pH block is used, which is far smaller, likely around 10ml. I don't prefer the smaller block.

I just suggest this in case while you're deciding that you might want to try the drop tests again and see how they work for you. If you can find them that is.

 

[loop_pea]

I'm amazed that you found that information. However, the 288 is not current/valid anymore. We had a Bek 458, which we were looking at until a month ago, where it was replaced by Bek 623 from 13/06/2012. Don't know if you can read the Danish here, but you may get the values: https://www.retsinformation.dk/Forms/R0 ... 42195#Bil1

For indoor pools the FC limits are 0.4-1.5 (I'm amazed that they can sanitize at those levels if a lot of people are bathing). For outdoor pools as ours it is 1.0-2.0. CC is <0.5.
I have been very much aware of all the rules because we have been struggling/fighting with the authorities about our pool and approval of this new upgrade for more than 8 months.

I'll see how it goes with the sanitizing. I think we can manage to keep it clean using 1.0-2.0, but I would prefer to have more "room" to play in with a larger interval. However, with the Autodos M2 system, we may be able to achieve rather stable values, once we've gained enough experience with it and are able to properly calibrate the chlorine electrode and the pH.

BR, Martin

I'm so glad my pool isn't in Denmark! I wouldn't be able to keep within the law. You definitely need automatic dosing to keep everything in such tight ranges, and we don't have that.

Since you will be measuring FC at around 2ppm then I think you do need a photometer. They work really well in that range, and having digital measurement eliminates variability due to bad eyesight, colour blindness or lighting. We use a Lovibond checkit 3 in 1, which is their basic model that checks FC, pH and CYA. I like the CYA test very much. It seems less subjective than the black dot test so long as you have a consistent technique (you have to shake it up and retest a few times, the equivalent of pouring it back and forth in the black dot test).

We use a tablet count method for TA and CH which is a tablet version of the tests they recommend on here where you add reagent and look for a colour change. Those were very cheap to buy.