I live in SE Michigan and have a well, so our water contains a lot of sediment and rust. We have a fairly complex filtering system for the inside water and also have a water softener, so we cannot use the inside water for filling our spa. Our outside spickets bypass all of the filtration, thus the water contains a high amount of iron.
The first time I filled my spa, I used a cheap attach-to-hose filter I bought designed for filling spas. Needless to say, I got what I paid for and ended up with water that had a slightly red hue after I'd filled the spa.
I decided to "build" my own filter to remove the iron and other sediment. For about $50 and a trip to Home Depot, I put together a dual-stage filter that resulted in crystal clear water on my second tub fill.
In case there are others out there who encountered the same problem as I did with bad water and a poor filter, I figured I'd post the recipe here.
(2) GE GXWH04F 10" filter housings (any brand will work)
(1) 15 micron spun polyester sediment filter - (I used a GE FXUSC)
(1) 5 micron sediment filter - (I used GE FXWTC)
Various fittings to make the connections to the filter housings and a 3/4" hose (see picture)
First, using the fittings and a coupler, I connected the two filter housings together. Next, I placed the 15 micron poly filter in the first housing to catch larger particles. In the second housing, I placed the 5 micron filter. Then I just placed the proper fittings onto the ends of the housings and hooked up my supply line and my fill hose, and filled 'er up.
Hope this helps someone.
Jason