The mangroves will not be under the tank. The 29 will be next to the display tank so the mangroves will have plenty of space and light. I started playing with the pvc in March and didnt finalize the design until May. I have cut and drilled the dead rock in every way possible, and put about 60 hours into it. Im 3 1/2 months into the build, have put a ton of time into it, and Im still atleast 9 months away from buying fish or invertebrate #1. I will have about 219 gallons of water minus the 200 lbs of rock. 2 maroons, 7 jawfish, a few barnacle blennies, 4 shrimp gobies, and a few dragonets in no way, in my opinion, is too big of a bioload for this set up. I would think a snowflake moray, a trigger, and a lionfish would be suitable in this size tank. I cant imagine these little guys producingas much waste as those would. At any rate, if my bioload is too high, Ill scrap the dragonets, do more water changes, add a skimmer or an algae scrubber, or add another tank to increase my water volume even more. This stocking level will be reached very very slowly. I want to see how far I can push a macro/mangrove filtered tank. If I am wrong no worries. An answer can be found. My turtle requires a ton of maintenance as he is more of a pig than any fish ever could be. The algae eaters keep his tank glass clear, the guppies and ghost shrimp eat his poop, and the bamboo filters his water a bit. The rest i make up with water changes. For his tank carbon is almost useless. Water changes are the only way to stay ahead of him.