OK...so FC at 14, if you measured that using the FAS-DPD test, what is your CC level? Also, have you added any PH down to reduce PH from the original 8.2 to 7.8? The yellow OTO drops only measure FC to 5ppm, so that's why you seeing orange.
You have three things working against you...if you are using powdered chems to adjust PH, it takes a while to clear with the intex filter. Your PH is on the high side and if your CH is high it could be calcium or it could be dead algae that may just take a while to clear with the small filter.
Either way, sounds like you'll need to do an overnight FC loss test, report back your CC and CH levels. If it all ends up being within acceptable levels, it may just require addt'l pump run time and cleaning your cartridge often.