I'm trying to find the "best" off-line erosion feeders for our 27000 gal in ground com pool and 2000 gal hot tub. Right now we're using the rainbow 300's but seem to have problems with the valves opening, closing or limiting flow. They are controlled by a BECYS automated controller that basically opens an irrigation valve allowing water flow through them. I'm sure there are many other variables to consider but first wanted to make sure that we were using the proper feeders. Any suggestions???