Thunderfan
Active Member
I got my tank ready for my aqua scape done now I just need water. I don't have a ro/di yet so I will be buying it from a lfs. Question is how much do I really need? My display is 75g my sump is made from a 30g which probably has 20g capacity when running. I know rocks and sand will displace water but, how much? I have 80 pounds of sand and about 80 pounds of rock between the display and sump. How much water would I need so I don't have 20 gallons left over but I don't have to run back to get more?
