I don't really know much about these filters though, and I don't want to screw up my HVAC. I found a bunch of options on ebay for custom-made filters, but it's hard to know what's junk and what isn't. I also read that when you switch from a media filter to an electrostatic/reusable one, the max depth is 2 inches.

In case it matters, my house is old but mostly remodeled and has floor returns and registers near the ceiling.

So my questions are:

1. Is it true that reusable filters are max 2" deep?
2. Do I need electrostatic? What's the benefit?
3. How do I pick a quality filter?
4. Is it ok for me to switch to a reusable filter?

Any other info would be greatly appreciated.

Thank you!

air sealing return & ductwork is a long term
improvement. you want to stop 'stuff' from
entering duct system & bypassing filter to
collect on coil. Mastic is the best product
for the long term seal. I like paint on mastics
& Hardcast brand 1402 mastic tape.

electrostatic filters & uv lights make lots
of claims. but if ducts/returns are sealed...
both are not necessary.
you'll find that folks who sell & have
bought these items think they are wonderful.
having been in the unbiased field of work I'm
in...the investment in mastic sealing & media
filter is what really works.

$40 per media filter twice a year...worth it
to me.

best of luck.