Plumbing question adding a filter pipe diameter concerns.

I am adding a whole house filter to my plumbing. The pipe is 1 1/4" coming from the well pump. However the filter inlet size is only 3/4". I was planning on putting the filter between the pump and the pressure tank. Will this cause an issue with the different pipe sizes? 1 1/4" - 3/4" - 1 1/4"

Or should i just put the filter after the pressure tanks and before the house supply line?

Put it in after the main shutoff to the house.

I’d recommend a larger filter, which has the correct size of fittings, the “whole house” filter you have is intended for use on a house which is connected to a public water system. typically a residential service is only 3/4 or 5/8-inch.

You have a well and pump, assuming the piping is sized to the pump, the flow will be higher, and the smaller filter may restrict the flow.

Look up the pressure drop through the unit for a specific flow. Determine if you want to lose that kind of pressure at your anticipated flow. Depending on how substantial it may be, an adjustment in your pressure setting may be enough to compensate.

I assume you would have your exterior hose spigot or irrigation system upstream of the filter.
Just because you have a 1 1/4" coming from the well pump doesn't mean your using more water than the typical public water supply. Or are you?

Do not put the filter between the pump and pressure tank, you will prematurely wear out your pump. Install it after the pressure tank

Thank you all for the input! Helped a lot. Thought i would share a few photos of the finished plumbing. I sill have to add the support brackets yet.

With those pressure gauges you have, up & downstream of that filter, you can monitor your pressure drop across that filter.

Thanks Diehard. I am going to write the "optimal" pressure on the tee also, as it will give me a better indicator as to when i need to change the filter as well.

Of course it will vary greatly based on the flow rate. (At zero flow, there should be no difference in pressure readings, except for the difference in elevation between the 2 gauges.)(2.31 feet = 1 psi)

It would be nice if you could find the specs on that filter from the manufacturer, as to pressure loss at a specific flow. And even better, what they feel is the recommended differential pressure for when it should be replaced. And/or you could go by your observation of lowered flow and pressure at the point of use.

Just some food for thought.