bucca :
I recently bought an ekwb extreme liquid kit- I've noticed the pump is not variable speed. no way to change pump speed except with fan controller.
If you're seeing this, blame your motherboard. Lots of mboards don't have PWM support on all their fan headers; they change voltage output instead. Since the pump isn't drawing power from the mboard, this won't help you. Many boards I see only have PWM support on the main CPU fan header and not the rest. If you want to change the pump speed, plug it into your CPU header and move your radiator and other fans to the system marked headers. If you're using such a massive radiator, your fans shouldn't need to change their speed much, so voltage control should be sufficient for them.
bucca :
and in the long term hard tubing would not collect sediment
The only sediment in the loop is what you originally put in there. If you didn't rinse out the rad, pump, reservoir, and waterblock before you assembled it, I recommend flushing your system and doing so now. Only used distilled water to fill the loop. If you're talking some kind of chemical precipitate, that's a different issue. Also, if you do have any foreign material in your loop, it's much more likely to collect in the waterblock fins instead of the tubing.
bucca :
hard tubing seems much preferred
Preferred by whom? Yes, it can look nicer and neater in a case, but it's also harder and more time consuming to deal with.
bucca :
not sure if I can use the 360 extreme kit fitting for hard tubing
No, you can't. Those are compression fittings for soft tubes. However, you can replace those with hard-tube fittings if you want.
bucca :
so far very hard to reach ek so any help is appreciated
I've not had that problem. How have you tried so far?