You should have a black hose with a knob that has numbers on it.
To see if it is working turn the knob to 0. Take the lid off of the top, turn the pump on, then turn the knob up.
You should see water entering the chamber, the higher the number the more water enters the chamber. If it isnt working this way there may be a problem.

If I take the lid off while the pump is running and turn the knob to 5 the canister fills with water. If I turn the pump on and then open it there is no water in the canister until I open the lid. Shouldn't there always be water in it?

Sounds like the return side is clogged.

If the pump is on and the 320 is set to 5, open the lid as you did before. Let it fill with water. Turn off the pump. How quickly does it empty?

Scott

It empties in about 10 seconds.

How old is this? Is this a new installation? What setting is it normally set to?

Scott

The pool was put in last fall. I normally set it to 3.

What pump?

Scott

We were having the same problem with our Rainbow chlorinator - we fixed it by running our pump at a higher speed. We have a Pentair VS and run it on high 2 hours in the morning for the cleaner, then at 2000 for 9 hours, then another 3 hours on the higher speed. Our chemicals got all out of balance from our experimenting with the chlorine, but we've finally fixed it.

I'm not familiar with the 320, but it could be an air lock. Have you bled the air out with the relief valve while the pump is running?

Jay and tswank,

The 320 injects water up from the bottom. The return valve regulates the return flow. The trapped air prevents the higher level tablets from being washed until the lower ones erode and ensures that when the pump shuts off, the water in the holding tank drains out.

This keeps the tablets from continuing to erode which would create a very high blast of chlorine at startup and since chlorine is corrosive, would needlessly work towards destroying over time, the chlorinator.

The effect I just mentioned is what kills Hayward CL200 and C220 series chlorinators.

I think the original poster has one of two issues. The more likely is he has either a two speed or variable speed pump that does not run on high speed long enough. The other is a possible failed check valve at the bottom. It is why I asked him what pump he has.

The 320 require water to move past it at at least 4 feet per second to work. Faster is better. It scoops water into its tank, The tank is sealed air tight by the cap. Slow moving water will not compress the air which would allow water in to wash over the tablets before returning to the pool.

This didn't use to be an issue for many pool filter systems since the vast majority were single speed pumps.

Welcome Jay, by the way. :-)

The 320 can be reversed to have the water cascade from the top down. This helps with erosion on lower flow rates. Simply use the 18" hose section.

We had to do what repair_guy suggested... made the 320 a top feed system... works great now for low GPM. We mostly filter on 1500 RPM (VS-3050), and have to keep 4 pucks in the 320 in order to get a good dose of chlorine.

-Gorilla

Hi everyone, thanks for all the useful info on this model. I am having the same problem with my 320. The pool was installed in October of 08, 23K, plaster, Hayward Supper II 2hp, Hayward C4025 cartridge, Nature 2 and an ozonator. Lots of sun and heat here in Texas. The first year and a half were no problem, kept the pentair on 1.5 to 2 and rarely saw anything other than a few small spots of yellow/brown algae in certain shady spots on the wall and almost never had to shock the pool. I let the chlorine dispenser get empty a month or so ago, boneheaded and no excuse. Needless to say the first clue was cloudy green water. I worked with local pool supply store and finally got everything back in balance and with a lot of attention it cleared up. My problem has been that ever since, my chlorinator has not been supplying enough chlorine to keep the free chlorine level above .5 even though I have the pentair set to 5! I recall that when I used to check the feeder it always seemed that the stacked pucks showed even usage, they all shriveled into a tall tree. Lately the tops pucks barely, if any, shrink at all as they travel down to the bottom of the feeder. I've bled the feeder several times by slowing releasing the cap until fumes followed by water sprays out. Any suggestions would be greatly appreciated. One other odd note, the psi on my filter dropped from the usual 20 to 19 and has stayed there. I know that a dirty filter will cause the pressure to rise but any ideas on what would cause pressure to drop? During a particularly nasty storm, we got a ton of leaves in the system and the pump lost prime either while running or at start up and ran far a good day dry which I know is bad but it still seems to be working and there are no leaks. Again, any and all advice is appreciated.

The gauge is aging. Don't sweat it.

Read my post on how it works that is earlier in the thread.

Who long are you running the filter?

What are the numbers for your chems?

Is your 320 a top or bottom fed? If the black hose is about 8" and goes to the top of the tube its a top fed, if its only about 4", its bottom fed. Most are bottom fed.

Scott

Scott, thanks for your reply. It's always nice to be able to talk with someone knowledgeable who is not trying to sell you something.

Happy on the gauge then!

I run the filter for 7 hours at night though about 4 in the winter.

So from reading your post, the higher pucks are not supposed to be eroding at the same rate as the bottom but shouldn't having the flow meter set to 5 increase the water level up to the top or am over-simplifying things?

I have to admit that I haven't had a reading in over a week but I am getting one later today - I don't have a test kit that gives anything but colors so I take my water to the pool store where the guys obviously know a little more than me but they are also in the business of selling things I may or may not need. So far, my relationship with them has been pretty good.

It's a bottom feed. One question I do have regards having the lid off the 320 while the pump is running. I set the flow valve knob to 0 off, removed the lid and turned the pump on and the tube filled with water in seconds and started to overflow. I shut the pump down and the tube drained in approximately 8 seconds. Am I do something wrong? Could you explain the process?

Thanks again for your time,
James

Scott, the chems are
Free chlorine of .4
Combined .2
PH 7.8 (adding 2 lbs of ph minus since I have that but am out of muriatic acid)
Hardness 300
Alkalinity 80
CYA 100
Phosphates at 300 ppb (i will be adding Phosfree)

Phos Free will help. It will leave a milky goo at the bottom as it captures the phosphates. Vacuum it to waste.

Lower the water and add fresh too. The stabilizer level is too high. Dilution is the only method. I prefer to see it under 50.

The use of pH Down is fine. Easier to handle too for most people.

Check your fill water's hardness level. It would be nice if you lower that to about 200. The high pH wil cause scaling to form.

Scott

Thanks again for your time Scott. So would it be a fair assumption to make that I created this stabilizer problem when I was trying to clear up the milky green water by shocking it too many times? Is that high stabilizer level now defeating my 5 setting on the pentair by tying up all the chlorine I am trying to add?

To dilute the water, how much would you recommend I drain? 25%? Since I have a cartridge and don't have to backwash, I'm not very experienced with pool water drainage. Would it be too harmful to reintroduce that water to my lawn? It's certainly been dry enough down here that any water would be welcome, especially 6K gallons. Is it possible to turn off the skimmer return and just use the drains and at the same time go ahead and start adding water via hose at the top or do I have to get it down first and then start filling - just wishful thinking I guess as I really wouldn't know when it was 25% replaced?

I would assume that I don't wont to add any trichlor or shock until the water has been replaced as this would just raise the stabilzer level. Should I just add some chlorine bleach in the mean time since it doesn't contain stabilizer or is that a no no?

One more pentair question. Are the upper pucks not supposed to be eroding at the sam level as ones at the bottom of the feeder? That's what is happening now. The tube is slowly getting lower but the top pucks don't show any wear and in the past I always noticed at least by the halfway point in the tube, that all of the lower pucks were showing similar erosion.

Thanks again,
James

There should be a small plastic puck-type spacer in the bottom of the chlorinator stack to allow water to flow under the bottom tablet. With age and chlorine on it all the time, it can crumble breakup and disappear. It then needs to be replaced by dropping in a new one.