I got my the other day been running on my 40B for 4 days now.
When I first got it, it was wet inside I guess they test run it before they shipped it out.
The o-ring and inside on the side was oily. Filter didn't come with any carbon or bio ball.
It did came with 3 white floss pad.
So far so good this filter is like a ninja I can't hear a thing sometime I wonder if this filter is working/on or not. Lol I must say the flow suck at 200+ gph this thing is weak.
If I was to guess the flow rate on this filter I would say about 145+.
This filter will be nice if there a carry handle so you can pick it up.
Here my media set up.
Bottom: ton of floss
Middle: floss, bio ball
Top: bio ball, biomax.
The skimmer on this thing doesn't work for me since the water line is high.
The reason for your low flow is the way you set up your media.
Normally if you are using high density filter floss, which is very restrictive in regards to water flow rate, you want to keep it overall very thin. The denser the material then the "thinner" you need to use for those pads.
Also there is a bit of a problem with filter floss. Usually it is very dense and will filter out everything. The problem is that large particle will clog it faster than smaller particle. If you have a LARGE space to use filter floss, such as a modified circumference bucket filter like a fluval fx5 or the odyssea 500 then you can use the dense floss as the first line of filtration.
If you are using a canister, then placing that dense floss first will make it clog to quickly as there isn't enough surface area for that floss. Which is why in canisters most users will place the dense floss last.
Typical setup for a canister filter is a thick piece of low density mechanical filtration. Usually a very porous and coarse sponge to fill the entire first tray.This allows that sponge to collect the bigger particulates first without clogging. The smaller particulates in the water will be later caught by the denser floss. After the coarse sponge, one then places the bio filtration media. This is to allow the bio filtration to eat up as much of the ammonia and nitrites as possible. During initial setups, many users will place chemical filtration next in line after the bio filtration. This is because there may not be enough bacteria built up on the bio filtration to completely eat all the ammonia and nitrites. So a chemical filtration method, such as using zeolite, is needed for a bit. Once enough bacteria has formed, then the chemical filtration can be swapped out for more bio media if desired.
Final filtration for a canister filter is typically the super dense filter floss. Only a very thin layer of such material so as not to overly restrict the flow rate. Nor by this point should there much particulates needed to be filtered out except for the very small particles.
Eventually over time the filter materials will clog up. The coarse sponge filters are easy to clean. Just squeeze out and knock off all the gunk. The dense filter floss can be re-used after cleaning, but is typically more of a hassle than it is worth. Easier to just toss the dense floss and replace it new. The amount of bacteria lost over doing this, as some will also grow on the dense floss, should be negligible.
So for a bottom up canister like the sunsun you want to stack your media like this:
Dense Filter Floss
Chemical (optional or more bio)
This gives you the optimal filtration for these styles of filters without overly restricting flow rates. Give that a try.