Just wondering, aside from the filtration which looks to be doing a very good job...are you reducing waterflow by those 2 valves or does the pump have settings for 1/2 power, 1/4 power, full power?
If you reduce flow by those valves, you'd be creating quite some pressure in the pump with 2 results:
1. You reduce the lifetime of the pump by putting quite some stress on the impeller, shaft and fittings.
2. I assume that your pump would also draw more power and generate more heat compared to running non-restricted.
Better solution would be to put a T just after the pump, off the main line that goes up to the filter, put a valve over there and return that one to the sump/tank.
The main lines to the filter fully open and then regulate the flow by opening the valve 'off the T' to the sump/tank.
This way you never put stress on the pump and you have better and easier control on the flow to your filter.
You could still use the 2 valves you got to regulate it between the two outlets into the filter.
Other than that, perfect DIY solution for your tanks...
Cheers,
Luc