I read about AC70 conversions and other HOB Refugiums for my 2 year old reef tank. I wanted a small place to house some chaeto and culture some pods. I ran across a HoB Breeder box from Finnex on eBay and eventually bout it through the manufacturer's online distributor. I got the large version (1gal) with water pump (40gph) instead of air pump/gravity flow. It ended up around $31 including shipping. Just thought I would post in case others are interested in something similar. Not sure on linking policies but I'm not affiliated with any of these companies!
http://www.aquavibrant.com/filtration/refugiums/finnex-breeder-box/finnex-breeder-refugium-box.html (OOS right now)
Pics!
http://www.aquavibrant.com/filtration/refugiums/finnex-breeder-box/finnex-breeder-refugium-box.html (OOS right now)
Pics!