3rd pic...all 3 species

Why are you trying to keep them all in one cage? I mean, by the looks of it, the housing you have setup is inadequate for any of the species alone, and putting them together insures that they will be stressed, which is what causes other problems in reptiles. I would do some research on the animals and then house them seperately in more adequate conditions. Tegus like an environment where they can dig (cypress mulch or a good soil is good for them) and get to an area of hightened humidity (actually good for basically all reptiles). Iguanas need an overall very high humidity, which your substrate cannot provide. The iguanas also need good uv lighting and whatnot. Plus, hidespots are a must. The more the better...and they should be low enough that the lizards can feel them on their backs.

I know my installation is poor, and it was NEVER meant for iguanas ( if i need to change something fot the tegus, i can do it now). The 2 iguanas are being kept in there because the other 15 iguanas kind of like kicked them out the group and would attack these 2 none stop, if i hadnt removed them. Problem is i dont have enough space for another big cage to hold these 2, and no one who has the responsability enugh is willing to keep them. Thats why i put them (until i find a solution) with the tegus. Although they do seem to be ok, sleeping with each other, sharing food dishes together...i mean, none is intimidating the other

lol thats funny, 15 igz and tigz liven all happly ever after. Grow em all big and post pics. sounds like you need to move into a much larger house though. or take the sledge out and make some new rooms. that was my plan at first with what i built. but g/f wouldnt let me so i moved it into the basement.

Okay, I understand that. I do think it is pretty important though that you get them onto a better substrate. Probably either cypress mulch or good dirt would be the best choice. Something that they can dig into to get moisture from.

Isn't it funny how one small pet (for me a lemon toad given as a present decades ago) can turn into a menagarie? I went to a natural history museum with live exhibits the other day and I was bored, because the animals I now have at home are more exciting. What, there's a cricket in your jello? well, at least it's gut loaded.