I have several Rainbow 320CN in-line erosion feeders installed at various pools. Two give me problems, I'm hoping someone can give me some insight.
The first is on an outdoor spa. The water line and valve is installed on the lower port. The feeder fills at least part way with air on a daily basis, but still seems to work. This doesn't seem to be a problem. But when turned "off", it still feeds chlorine into the spa at a high rate. Seems to me it must be leeching it through the bottom? I don't have this problem anywhere else, as far as I can tell...what could be causing it, and how can I prevent it?
The second is more troublesome. It is for a small outdoor pool (50,000 L). The water line and valve were installed on the lower port; when this problem began I moved the line and valve to the top port. The problem is that the feeder fills with air very quickly - sometimes in as little as 8 hours. Once a certain amount of air gets in, it stops working. If I drop 4 pucks into the skimmers (illegal, btw), the pool's chlorine level will stay at the right level for about 3 days. If I drop 4 pucks into the feeder, I will have 0 chlorine the next day, and most of the pucks remaining.
Both have new O-rings on the lid and fresh teflon on all connections.
If I can't find the problem, perhaps a workaround solution - could I get away with installing an automatic air bleeder (like this one) on the feeder? I fear it will come down to that, or replacing with a non-inline feeder... Actually on that note, I wonder if I can just plug the bottom of the feeder and install an outflow line at the top port? Turn the inline into a regular feeder...just stuck to the pipe. :P