Update
Well I have the CSF500 hooked up to a new CL 60 acrylic I picked up for $10 that I am cycling for my sister's autistic son. The actual cycling is being done by my seasoned Sunsun 302 I pulled off my 100 Oscar tank along with half a dozen feeder fish to accelerate the process. Also a piece of sun dried Mesquite wood as I have noticed that new wood in its fungus stage detoxifies nitrates for a few months, how this works I not sure but I believe that in the first few month the log bark is deteriorated by a different bacteria that causes
denitrification. Anyway back to topic you can see the CSF500 under that tank and it runs very silent, primed easily with just filling with water where the bottom submerged motor in insta-primed and does the rest. The CSF500 really makes a visible current of water in the tank and you can feel the strong out-flow through its huge 1" inside-diameter nozzle, by comparison my Sunsun's small 3/8 inch diameter out-flow nozzle felt weak by comparison. The out-flow so strong on the CSF500 I had to remove the spray nozzle to lower the pressure and point the outflow at the panel. Even so I had some sand excavated sand off the bottom the next morning. I tell you one thing, the CSF500 has allot more outflow then either my Sunsun or my Magnum 350's.
Here is the funny true story, the sand I used was left over from a my 210 tank project and had previously rinsed and boiled months ago and stored a large pot in the garage. Apparently my 2 cats had been using it as a letterbox on occasion as there were only a few cat turds in there and easily removed. However the sand also had the telltale smell of dehydrated cat urine. Since the sand was otherwise clean I couldent imaging how cat ammonia would hurt and thought theoretically it should help. Well the tank was pretty cloudy so I hooked up the CSF500 first before the Sunsun and after 12 hours the tank was sparkling clear which means the circumference sponge and primarily the poly-batting outer layer is doing a great job. I think the CSF500 is going to make a very good primary filter for tanks 125 to 150 gallons IF modified. It seems to me to be the combination of the large 300 square inch circumference design mod which is easy to do with a pair of scissors, and the extraordinary high flow due mostly to its bottom submerged motor design which pumps water rather then draw water like lid top dry prime motors. Anyway unless there are unforeseen issues about the CSF500 that havent occurred yet, so far I think CSF500 has taken top place above the Sunsun as my most "all around" effective, easy to clean, affordable, and powerful, clone circumference design filter available. For the price if modified, I really think its a winner and knocks the ball out of the park.
PS- the stand you see is not the stand I will be giving my nephew as it is being refinished. The stand you see below is modified furniture. Notice my weak attempt to duplicate matching center legs, but I think once matched stained they will look OK.