Here is a before and after picture. The equipment closest in the image above is the spa equipment. The swimming pool equipment is in the back. The spa used to have an old, single cartridge filter and the floor heads did not work. The spa pump had sprung a leak, the return side valves and the heater bypass valves were the old rotary style handles, which were binding up. 

I installed a new, larger Hayward cartridge filter to replace the old single cartridge bullet style filter. The old filter was undersized to the pump. The equipment is over 30' from the spa and including the run through the heater, it is a total of 50' that the water must travel. Because a high head pump is required in this application, I matched the filter based upon its flow rate to the pump. I replaced the old pump with a new Hayward, Super II and put down a new concrete pad for the DE filter to sit on, so the pump and filter were no longer crowded on a single pad. The A & A floor head valves were also replaced for the swimming pool and the spa. New Jandy valves were put in in the return lines, to replace the rotary style valves. Jandy valves can be rebuilt and the O-rings can be replaced if they leak.

This was a big job, but it was worth the effort. Replacing the floor head valves and all the floor heads at the same time, gives this customer a lifetime warranty on the floor heads and the gears in the valves. She simply needs to go to A & A's will call pick up in Phoenix and replace those parts for free as long as she owns the house.  

DE filters and cartridge filters must be taken apart and cleaned as part of routine maintenance. DE filters once a year,  and cartridge filters once every 6 months, or whenever the filter pressure goes up 10 pounds. Depending on the amount of dirt, debris or the bather load, etc, it may be necessary to clean a cartridge filter 3-4 times a year. You can backwash a DE filter, but residual build up of dirt, DE and debris, gets compacted between the grids and that can easily damage the grids. Opening the filter and cleaning and inspecting the grids must happen in addition to back washing throughout the year. Doing this maintenance can save you from unwanted problems and help save you money. Manifolds, air breather screens, cartridges and grids will last longer if they are kept clean and not allowed to get 'caked up' with debris. 

Anytime you have a filter apart, you should be inspecting the filter components for damage. Shown below, are some worst case scenarios. More than likely, if there are cracks, or tears to the degree shown in the images below, you may already have a green pool, or a dirty pool. Dirt and water would be bypassing the filter and blowing back into the pool. The idea of routine cleanings and inspections, is to discover potential problems early. What you will be looking for is hairline cracks in the manifold, or the cartridge filters rubber, or tiny tears in the DE filter grid material. If you see any kind of wear, or damage in the early stages, this is the time to replace the damaged parts before it becomes a bigger problem.