Rainbow tab feeder not keeping up

[Iowark]

I have a Rainbow tab feeder on a 10,000 gal pool and I have it set on 4 (goes to 5) and it is not keeping up. The CYA level is 50.

Chlorine levels:
1st night 8.5
2nd night 5.5
3rd night 3.5

I will bump it up with liquid chlorine and am just trying to use my chlorine tabs up. Plus, I am trying to get a feel what to set the tab feeder on when I go on vacation.

Any suggestions?

Bobby

 

[duraleigh]

You may have algae that is consuming your chlorine. Posting a full set of test results...especially CYA and CC's, will keep us from just guessing.

 

[Iowark]

FC 5.5 ( add liquid bleach to raise it from 3.5)
CC 0
pH 7.5
T/A 90
CH 350
CYA 50

Might ask the pool builder to check it

Thanks,
Bobby

 

[duraleigh]

Hi, Bobby,

Good looking results. There's nothing there that would indicate algae (nor any other problems) that I can see.

Only possibility I can think of is something blocking the flow thru the chlorinator.

 

[Durk]

Is this a new pool? If so, check your installation. They can be installed backwards. My Pentair can be hooked up two different ways for 1" or 3" tabs depending on where you attach the hose.

If it is old, take it apart and verify the check valve on the bottom of the unit where it screws into the return line. Then check the control valve (the one you turn it on and off with) for good flow. Compressed air is a big help here, if available. Either of these can get clogged up. Some cheapo tabs just take a long time to dissolve--or maybe they just decided to leave out some of the chlorine.

All these are just some of the reasons I took out my chlorinator and stopped using pucks except when I travel for more than a week--and then I use a floater.