By my calculation, I will need 6.1 cartridges of Dow 795 for this. To make sure I have enough, I'll be ordering 8 cartridges. A contractor that I know is looking into seeing if he can get them wholesale for me. If not, sealant will run about $70 - $85 depending on where I order it from. I could theoretically try to use Dow's Contractors Weatherproofing Sealant instead of the 795 and cut about $25 off the cost, but I'm not sure it would work as well on the slate. Add the $50 for the original purchase of the tank, another $12 for the side panel of glass I broke, and possibly another $128 for a new front pane so I don't have to see scratches every time I look at this tank, and I'm seeing $265 so far without the stand or sump yet. The wife's not going to like me, but I'm looking forward to seeing what this is going to look like finished!