The holes are 4 ft apart if that gives you any idea. lol. I put them to where they will be right beside the barrel biotowers when flowing into the sump. Remember the sump will be relatively small for this build. Just a 300 gal trough with two 55 gal barrels on top. I'll be making some pretty complicated chambers in ther sump. The filtration for this thing will be a bigger nightmare than the actual tank. The tank is plain and simple, just takes hella long to build something that massive all by yourself with minimal funding. Fish are all doing fine waiting on their new home. When I pull the cover back on the pond to feed the fish it's like the oscars and the big boy are like hurry the hell up with our new house. I don't think I'll be putting the oscars in though. The 350 pond might just be their new home. Still haven't decided yet. Either that or I will put them in first. It's all up in the air right now. I have $140 saved up from my bday, and by the end of next week after donating plasma and cleaning several tanks that should be up to $230. I'm going to keep saving up until I have the $320 needed for the blue max to seal it up completely and just get it all at once. I might as mentioned get an extra gal shipped early so that I can play with it a lil first. Plan on making a small box to spray it in and see how well it works. maybe more than one! I might also get a small scrap of acrylic so that I can try that out as well. With months, and months of building this thing I'd hate to make a big mistake by not sealing it right. So might costs me $50 or more to test it out, but it'll be worth it!