Sediment removal at the point of entry is the foundation of every treatment train, protecting appliances, softener valves, membranes and every cartridge downstream. It is also where installations most often go wrong, because the housing gets chosen for the space available rather than for the flow the house draws and the load the water carries.
Size on flow before anything else
A whole house filter has to pass the peak simultaneous draw, not the average. A slim housing has a modest flow rating and becomes the restriction as soon as a shower and a washing machine run together, which the household experiences as poor pressure and blames on the mains. A large diameter housing flows far better, holds much more dirt so cartridges last longer, and costs little more. Where demand is genuinely high, twenty inch bodies or two housings in parallel are legitimate answers.
Choose the rating from the water, not from ambition
The instinct is to fit the finest cartridge available and it is usually wrong. A very fine element on water carrying real sediment blocks in weeks, throttles the house and costs more to run without protecting anything extra. Match the rating to what the water is actually carrying and to what the next stage needs. Where the load is heavy, stage it: a coarse cartridge first to take the bulk and a finer one behind to polish, which makes the fine element last many times longer.
When cartridges are the wrong format
On a well carrying sand or silt continuously, cartridges become a weekly chore and the right answer is a backwashing media filter that cleans itself, or a spin down separator ahead of everything for coarse sand. The signal is simple: if changing cartridges has become a routine rather than an occasional job, the format is wrong for the load. Before installing a backwashing vessel, check that the pump and the well can deliver the backwash flow the vessel needs for its full duration.
Installing it so it stays easy
Point of entry, after the main shut off and before the water heater, the softener and every other stage. Isolation valves either side and a bypass, so a cartridge change is ten minutes rather than an afternoon. Clearance below the sump equal to its own height, or the element cannot come out. A bracket carrying the weight rather than the pipework. And pressure gauges before and after, which turn changing the cartridge from a guess into a number. Our whole house filter guide covers what follows this stage.
Questions people ask about whole house water filter for sediment
What size housing should I fit?
One rated for the peak simultaneous draw of the house. A large diameter body flows better and holds far more dirt than a slim one.
What micron rating is right?
Match it to what the water carries and what the next stage needs. Very fine cartridges block quickly and throttle the house for no extra protection.
When should I move from cartridges to a backwashing filter?
When cartridge changes have become a routine chore, typically on a well carrying sand or silt continuously.
How do I know when to change the cartridge?
By the pressure drop across it, which is what gauges either side of the housing tell you. Appearance is a poor guide.