Not sure I'd pick the MJ1200s over the 900s.... (fwiw
I have 1200s now).
The 900s run 85% flow, with about 40% of the electrical draw. If I were starting new I'd go with 9s.
I think 2x230gph plus the return from his cannister (take that media out! btw
) will give him close to 10x turnover.
Adding a sump with return pump would be nice...
Also be careful with the sand at HD
- make sure its calcium based, not sillicate based. Most of them will say "contains no sillicates" on the bag somewhere.