Offline Chlorinator, check valve & hartford loop

[Gepool]

Dear all, I will need you valuable knowledge one more time. I have an inground pool and the machinery room (filter, heat exhanger, pump) is also below ground. At the moment, I am putting the appropriate ammount of chlorine tablets at the skimmer.

I am planning to install an Offline chlorinator, more specifically the Hayward CL220. The chlorinator onlet will be put before the filter and the discharge fitting will be placed after the Filter, and after the Titanium Heat Exchanger.

According to their FAQs (Hayward Pool Products - Contact Us - Frequently Asked Questions):

CL220 has a check valve assembly built into the discharge fitting. In addition, the black tubing, on the discharge side should be looped. This is called a “Hartford loop” which helps prevent chlorine gas from getting into the equipment.

On the "hartford" loop stated above, do I have to make the loop of the black tubing big enough in order to exceed the water level of the pool? In case that there is no option to do that (inground machinery room) what are the alternatives?

thank you for your time.

George

 

[mas985]

On the "hartford" loop stated above, do I have to make the loop of the black tubing big enough in order to exceed the water level of the pool? In case that there is no option to do that (inground machinery room) what are the alternatives?

No, you don't have to install the loop above water level for it to capture the gas. It will still trap gas. The only affect will be the gas will be slightly more compressed than if it were at the same height.

 

[JoyfulNoise]

Just note that your choice of chlorination method — stabilized chlorine tablets made of trichlor — does come at a cost. Your pool water will build up stabilizer (cyanuric acid) over time and your pool will require higher and higher levels of free chlorine to maintain the disinfection strength. Your location may have enough annual precipitation to help offset the ever rising stabilizer levels but if not then you will have to periodically drain the pool to keep the CYA at manageable levels. Trichlor tablets are also highly acidic and so it would be in the best interests of your pool equipment to have a serviceable check valve installed between the point of injection and any heater you have to avoid acidic water from back flowing into your heater when the pump is not running. The offline chlorinator may have its own check valves but those can fail over time.

 

[Toxophilite]

My 2-cents. I could never get a basic chlorinator to put out more than 1-2 pmm chlorine below 2000 pump rpm's, even on highest setting, and that's plumbed full-flow. They just are not designed for low-flow, and quite honestly, for TFP methods. To maintain a proper CYA/FC level per TFP method, you would need way more than a couple of tabs per week, which is going to throw your CYA through the roof in just a few months. Tab feeders are just not a feasible way to chlorinate your pool in the long run. Yes, they make low-flow models, and my PB eventually replaced mine with one and works beautifully now, but I'm still back to the issue that the only time I can ever use it is for low CYA situations to bring it back up, or, for vacation mode.

All that's saying is that if you get past the first hurdle, even getting sufficient FC from it in a bypass mode, you are still left with something that has very limited use. A SWG or liquid chlorine are already in your cards anyway if you plan to follow TFP protocol.

 

[Gepool]

No, you don't have to install the loop above water level for it to capture the gas. It will still trap gas. The only affect will be the gas will be slightly more compressed than if it were at the same height.

I can't figure out how this will work. if the loop doesn't pass the water level, won't the pressure from the pool water be enough to push the gas back? How does the loop works if it below water level? No air gap will be created.

Just note that your choice of chlorination method — stabilized chlorine tablets made of trichlor — does come at a cost. Your pool water will build up stabilizer (cyanuric acid) over time and your pool will require higher and higher levels of free chlorine to maintain the disinfection strength. Your location may have enough annual precipitation to help offset the ever rising stabilizer levels but if not then you will have to periodically drain the pool to keep the CYA at manageable levels. Trichlor tablets are also highly acidic and so it would be in the best interests of your pool equipment to have a serviceable check valve installed between the point of injection and any heater you have to avoid acidic water from back flowing into your heater when the pump is not running. The offline chlorinator may have its own check valves but those can fail over time.

Yes, I completely understand the problems and the downsides, unfortunately they are many. Since this year a gave my budget to turn my pool to a heated one, next year I am planning to add an SWG.

The first problem with the 3-chlor tablets already came up. Since 2 days ago I was putting my tablet at the skimmer. Now, since the pump is working constantly to maintain the temperature the tablets are resolving way to fast. I have to find a temporary solution to this. That's why I thought about the offline chlorinator.

 

[1poolman1]

Dear all, I will need you valuable knowledge one more time. I have an inground pool and the machinery room (filter, heat exhanger, pump) is also below ground. At the moment, I am putting the appropriate ammount of chlorine tablets at the skimmer.

I am planning to install an Offline chlorinator, more specifically the Hayward CL220. The chlorinator onlet will be put before the filter and the discharge fitting will be placed after the Filter, and after the Titanium Heat Exchanger.

According to their FAQs (Hayward Pool Products - Contact Us - Frequently Asked Questions):

CL220 has a check valve assembly built into the discharge fitting. In addition, the black tubing, on the discharge side should be looped. This is called a “Hartford loop” which helps prevent chlorine gas from getting into the equipment.

On the "hartford" loop stated above, do I have to make the loop of the black tubing big enough in order to exceed the water level of the pool? In case that there is no option to do that (inground machinery room) what are the alternatives?

thank you for your time.

George

Tab feeders, regardless of the installation, are not a good idea on a residential pool. They were initially designed for use on commercial pools where the pumps can run 24/7.

If you run your pool that way you may not have a problem but the built-in check valve will eventually fail and you will never know it until the very corrosive "soup" that remains in the chlorinator has damaged your equipment. Many times it is the quality of the tablets that are used. Some have more "filler" than others and that residue clogs the valve. If the valve fails it will allow water to "siphon" backwards through the system with the first thing that is hit is the usually the heater.

They are no longer legal in my area on commercial pools, but people still install them on a residence. If you want to use tablets, the best thing is to put them in a floating chlorinator where they can add a bit of chlorine (and CYA) directly to the pool 24/7.

 

[mas985]

I can't figure out how this will work. if the loop doesn't pass the water level, won't the pressure from the pool water be enough to push the gas back? How does the loop works if it below water level? No air gap will be created.

No! In a closed plumbing system, water only flows when there is a pressure differential as what is created by a pump. With the pump off, as long as the pressure is the same on the two ends of the closed plumbing system (i.e. pool water level), no water will flow. It doesn't matter the height of the pool water.

The only exception is when the plumbing is no longer a closed system such as when you open the pump basket. Then the relative pressure changes at that point and if the pump is below water level, water will start to flow out of that location and into the returns and suction ports from the pool. So in this situation, any gas and CL could be pushed into the heater but would quickly exit too so it shouldn't be an issue.

 

[Gepool]

No! In a closed plumbing system, water only flows when there is a pressure differential as what is created by a pump. With the pump off, as long as the pressure is the same on the two ends of the closed plumbing system (i.e. pool water level), no water will flow. It doesn't matter the height of the pool water.

The only exception is when the plumbing is no longer a closed system such as when you open the pump basket. Then the relative pressure changes at that point and if the pump is below water level, water will start to flow out of that location and into the returns and suction ports from the pool. So in this situation, any gas and CL could be pushed into the heater but would quickly exit too so it shouldn't be an issue.

Firstly, thank you so much for your time to explain this to me! I think I am almost there. So, in the best case scenario I should make the Hartford loop such as to exceed the height of the chlorinator itself, is that right?

 

[mas985]

No, it doesn't really matter as long as the loop part is higher than the connection points of the chlorinator to the plumbing so any gas rises from that point. Also, as long as you have check valve, you don't really need the Hartford loop. It is just extra insurance. Most pools don't have the loop with a tab chlorinator.

But if I were you, I would seriously reconsider using a tab feeder. As others have pointed out, long term, it will cause you more problems than what it is worth.

 

[ajw22]

I suggest you consider using floaters for the Trichlor tablets in your pool until a SWG fits your budget instead of the tablet chlorinator.

 

[Toxophilite]

I suggest you consider using floaters for the Trichlor tablets in your pool until a SWG fits your budget instead of the tablet chlorinator.

I'm with this! That will be several hundred dollars in chlorinator, pipe, fittings, plus redo with SWG later. And, the cost to drain and SLAM your pool will be on top of that, as tabs are the foremost lead-up to the need to SLAM. Put that money in the kitty for the SWG and focus on the future. There's options, easy options, that don't require any plumbing till then.

 

[JoyfulNoise]

Whenever I use a tablet floater (typically spring start up) it can take weeks for 5 tablets to dissolve slowly. And the water is definitely in the 70-80F range. Even in the summer when my water temp is closer to 90F, a few tablets in the floater will last more than a week. Tab feeders just push too much water through the column so the dissolution is much higher. Same is true inside a skimmer basket where there is a constant high volume flow of water.