joecoulson;4956203; said:NO = Normal Output Less expensive but less light output
HO = High output
If you get reg sand (don't get Play Sand, get pool filter sand) then you will have to use something else in the water to buffer the PH high for the Africans
If you get Aragonite (which is essentially crushed coral) it will buffer the water ideally for you and it will be hassle free. It also helps to maintain consistency with water changes and maintenance.
Ok ty. And to add to the barrage of questions

What can be uses as water buffers if I do go with Pool filter sand.
And if i do go with aragonite about how much will I need for 75gal(probable dimensions 48x18x21 will change if I buy from craigslist possibly)