The 525XL is 139 gallons total water volume. They are overpriced but really nice. I almost went with the SCA 150 and had it drilled for the synergy. Awesome tank. Congrats!!!!The only reason why I went an SCA Rimless 150 is b/c I not a fan of REDSEA systems, they are way overpriced in my opinion. I would prefer, to customize my own sump and tank even know they are great tanks but how many gallons are the 525 and the 750s?
SCA 150 RIMLESS Custom drilled for a 20'' Synergy Overflow box