HardTrance9 said:
Great answers!
DE ingredient is not easily find in this little town and the process for coating, etc., takes more time. Then the cartdrige seems to be very efective too but still takes some time.
Here pools are exposed to more dust, leafs, dirt, etc., so a ultra clean water is not needed because it is very difficult to achieve (unless it is enclosed or protected with some glass fences, etc.).
Keep voting!
Let's see overtime what the general opinion is... should be interesting!
I can't answer specifically but you did qualify very well eliminating "ultra clean water",
although I would phrase it "ultra clear water". The water can be "ultra clean" by virtue of good maintenance and proper chemical balances, but still have particulates in suspension. My expectations are very high for my water but it is virtually impossible to eliminate all of the extremely fine blown in and carried in dust and silt, even using a DE filter, going many hours a day, and backwashing frequently. People around my area use DE for the best water clarity, but from what many people report DE is not the "easiest" comparing my personal experience (DE for 23 years) compared to what seems to be the two easier of the three, i.e., cart and sand.
Most people can't comprehend how much silt/dust some of use have unless they experience the extreme situation and try to keep pool/spa and buildings (homes, garages, outbuildings, sheds) somewhat clean, i.e., only somewhat dusty. I have been using cartridge filters for two decades in my large spas. My main concern about a cartridge filter would be premature clogging of the cartridge fabric from excess amounts of silt/dust; excess being many times more dust/silt than most filters will ever have to deal with. Although my spa (and two others previously) are kept covered, most of the time, I think the amount of time the top is off allows enough silt/dust in to prematurely age the cartridges. This is a totally non scientific observation. BTW... some of my silt/dust seems to be finer than even DE.
My vote for
ease of maintenance, in the environment you describe, would be for sand. That is even if one is under extreme water restriction. Backwashing does use water but so does washing a cartridge properly. One solution for waste water is to return it back to the pool after "polishing" it using something like a Slimebag or use for watering plants. It seems to me that reusing water from backwashing is much easier done than reusing water from cleaning a cartridge.
It takes a lot of water for soaking and spraying to clean my spa cartridges for reuse.
Every cleaner I have does really well picking up sand and some of the silt. It is the very fine silt that makes its way to the filter that necessitates so much backwashing. I would think that some of that extremely fine silt would make it through a sand filter and not clog sand as fast as it would DE.
My vote for your criteria is SAND.
gg=alice