Capped line w/valve

[Motozoic]

I've noticed that there is an intentionally disconnected line with a valve on one end that seems to affect the amount of air being introduced to the main filter pump during operation. I'm hopeful that someone will have an idea what this was for because I'd like to fix the issue properly. It seems that former owners experienced an equipment failure or something broke and the solution was to remove and cap things off.

Thoughts?

 

[JamesW]

The valve went to a Rainbow offline chlorinator. The part clamped to the pipe also went to the chlorinator. I don't know why it's connected like it is.

Do you have a picture of the whole system?

 

[kadavis]

That line was the injection point for a ozonator. It actually goes down in the ground and tees into suction line. Patio pools used this system for years in Tucson.

 

[kadavis]

If there's no ozone connected anymore you could take the small control valve out and plug with a 1/4" plug

 

[JamesW]

What did the other line connect to. The one that's clamped to the pipe?

 

[kadavis]

They would run a line from the air relief on filter back to return to keep the filter from trapping air

 

[Motozoic]

Thank you so much for responding. The pool was certainly built by Patio Pools, as I have receipts from the original homeowner who had the pool built. Here's a snap of the main pool equipment. On the far left, not pictured is the Compool CP1000 and LX-100 power center. That thing seems to be working pretty well, although a bit dated. Adjacent to the right is the pool heater, which is some sort of Raypak device that works very effectively. In the middle you can see the main pump that runs when the pool is filtering and also when the spa is turned on. It appears to be an A.O. Smith unit, single speed, works fine at the moment. Next we have the Pentair Triton II sand filter unit, model TR-100. Not very easily discernible, but present, is another pump adjacent to the filter which seems to turn on whenever the rock waterfall is enabled.



So, what is the correct action here? Do I need to route the plugged and clamped off connection back to the air relief on the filter? I'm not entirely sure where exactly that might be, but I'm certain I could figure it out.

There are some additional components located very close to the skimmer in the pool - I'll have to figure out a way to post those images here since I appear to have run out of storage space.

 

[JamesW]

If the ozone was being introduced to the suction side of the pump, the air relief might have been to bleed off the ozone in the filter.

At this point, you don't really have to do anything. Just make sure that the small valve is closed so that air doesn't get sucked in.

You can remove the valve if it won't close completely and install a plug.

If necessary, you can cut off the cap and glue on a new cap. It looks like it's probably 1.25".

 

[Motozoic]

Thanks, I'll probably just cap it off with an automotive rubber/silicone cap for now. My intent is to automate some of the chemical dispensing to reduce my time spent maintaining the pool. I've been looking at medium pressure UV lamps, salt chlorine generators, and automatic muriatic acid dispensers. Do those items sound like a good update to the system? Of course, the computer system would need to be upgraded... and I haven't quite researched that fully.

 

[tim5055]

Thanks, I'll probably just cap it off with an automotive rubber/silicone cap for now. My intent is to automate some of the chemical dispensing to reduce my time spent maintaining the pool. I've been looking at medium pressure UV lamps, salt chlorine generators, and automatic muriatic acid dispensers. Do those items sound like a good update to the system? Of course, the computer system would need to be upgraded... and I haven't quite researched that fully.

Skip the UV, you get plenty of it free from the sun.

A Salt Water Chlorine Generator would be a great way to automate chlorination.

 

[Motozoic]

After speaking to a friend about all of this, I think I'm just going to go for a Pentair Rainbow 300C chlorinator. The system was originally setup to use one and I like the idea of not having to dump buckets of chlorine into the pool manually... using tablets, instead. Are there any good computer controlled chlorinators available? Ones that sense the chlorine level and meter the output automatically based on sensor feedback.

 

[tim5055]

After speaking to a friend about all of this, I think I'm just going to go for a Pentair Rainbow 300C chlorinator.

This is the reason most folks show up at TFP, over stabilization because of trichlor tabs. Each tab you use in your 13,000 pool will raise FC by 4.2 and raise CYA by 2.6. The 300C holds 11 tabs, so each time you fill it you are increasing your CYA 28.6 In no time at all you will be in the 100+ CYA club

Are there any good computer controlled chlorinators available? Ones that sense the chlorine level and meter the output automatically based on sensor feedback.

This is the problem with truly automated chlorine addition systems. The only economical sensor is called an ORP sensor. With no salt or CYA in the water they can be used to correlate to a FC reading, but need regular calibration.

JasonLion said it best -

There are various known quirks with ORP sensors that can cause problems in specific situations. Non-chlorine shocks can sometimes cause high ORP readings, even when chlorine levels are quite low, leaving a pool unsanitized. CYA levels above 50 can reduce the change in ORP as chlorine increases to such small values that accurate automation is impossible. Readings vary from one ORP sensor to another and no reliable calibration standard exists. Therefore, ORP readings can only be taken as a relative indication and not as an absolute number. Dissolved hydrogen gas from a SWG can lower ORP readings, sometimes masking the ORP increase from chlorine production. ORP sensors measure extremely small voltages, so stray currents in the water can cause problems. ORP is very sensitive to PH, so you need to also have PH automation or FC levels can fluctuate significantly.

There has also been a running debate: Do ORP readings or FC readings predict proper sanitation levels more reliably? I believe that FC is a better indicator. Chem Geek discusses this further here.

Sadly sensors that can directly read the FC level are very expensive, thousands of dollars, and thus impractical for most applications. Without a FC sensor, ORP is the next best alternative, despite it's issues.

 

[Motozoic]

It seems that an ORP sensor is still something that requires frequent calibration and isn't exactly the best indicator either. So I'm not really sure what the best solution is other than to manually test water and dump pure liquid chlorine in to avoid hiking the CYA levels via tabs. Are there no tabs available without the addition of CYA?

 

[mknauss]

There are 'tabs' made of calcium hypochlorite. But adding calcium to water in Arizona is worse than CYA. It builds up quick with our evaporation and you must drain your pool.

Best method of chlorination in the desert is a SWCG.

 

[tim5055]

Are there no tabs available without the addition of CYA?

In it's natural state, chlorine is a gas. Many large commercial pools actually use gas injection systems to chlorinate their pools. Now, to change chlorine into something we can use at home it needs to be bound to something to turn it into a solid.

The "somethings" that are commonly used are stabilizer (also known as CYA), calcium, lithium, or --- get this water.

All of these add a little salt to your water, but they add something else.

Cal-Hypo add calcium

Tri-Chlor and Di-Chlor (tabs and most granules) add stabilizer

Lithium hypochlorite adds lithium

Liquid chlorine adds - water.

There are CalHypo tabs, but their chemical composition is such that in a normal feeder like the 300C they become a gooey/gummy mess and plug up the system. There are grinder feeders that use CalHypo tabs, but again instead of raising CYA they will add calcium which is already high in your Arizona fill water.

For my pool I added a Stenner pump to pump liquid chlorine on a regular basis rather than using automation. When the pump runs the chlorine is being added. It takes a little time to dial in the average use, but once you get there you can usually cut back testing to a few times a week. Stenner Pump Install

 

[Motozoic]

I don't think storing large quantities of liquid chlorine works for me since I reside in Tucson, AZ - the heat will waste it quickly. So I suppose that brings me back around to SWCG, as has been suggested.

I've looked at the Pentair IntelliChlor units a fair bit, but going that route requires a substantial investment in Pentair electronics.

1. Pentair 521247 Compool to EasyTouch upgrade kit with transformer, about $650. This is required to interface with the IntelliChem unit listed below.
2. Pentair 521357 IntelliChem Chemical Controller without pumps, around $1000.
3. Pentair IntelliChlor unit, IC20 is $750, IC40 is $850 - not sure which one is best for a 13,000 gal pool, although I've been told you want to run the larger unit because you're able to run it at 50% duty cycle and it will last longer that way or something, no idea if this is true or not.
4. Pentair 520500 ScreenLogic2 interface, about $420. Not a requirement, but allows control and status reporting over your phone and laptop.
5. Need a CO2 injection system, no idea how much that is or what device I could use yet.

So we're looking at about $3000 in parts and I'm probably going to sub out some of the work which will be another $500-1000 in labor. Sound about right? Anyone else in this boat before?

 

[mknauss]

You do not want the Intellichem. It is a mess as it tries to use an ORP probe to control your SWCG and the ORP does not work when CYA is in the water.

If you want to add acid - use the Intelliph. Also do not use CO2. CO2 only controls pH and does not effect TA. You need to control your TA as your fill water will drive up the TA which will make controlling the pH costly with CO2. Also, CSI will climb quite high with high TA.

 

[Motozoic]

Well, I was planning to drain the pool in Jan/Feb completely and starting over with the new system, so not using tabs anymore and hopefully not adding any CYA?

 

[mknauss]

You need CYA in the pool water. With a SWCG you want 80-90 ppm in Tucson.

See Pool School - Recommended Levels

 

[tim5055]

You do not want the Intellichem. It is a mess as it tries to use an ORP probe to control your SWCG and the ORP does not work when CYA is in the water.

I agree with this 1000%!!

Well, I was planning to drain the pool in Jan/Feb completely and starting over with the new system, so not using tabs anymore and hopefully not adding any CYA?

As Marty says, you do want CYA - just not uncontrolled amounts of it.

Unles your CYA and CH are already at astronomical levels, there is generally never a need for a full drain to start over. You only need to drain down to get to where you need to be. Let's say your CYA was 160. You can drain 100% of the water and then add CYA to get back to 80 or you just drain 50% of the water and you are there already. Draining to start over alwasy sounds better than it is in real life.