looking for tips!
The saltwater seems to be a bow front, although the picture on my phone is a bit skewed so I can't be sure. If it is a bow front, then I agree that you can't use it as a sump. I also see what appears to be a domino damsel in there, which will have to be removed before you add any other fish. A 36 gallon is too small for them and they get very aggressive. You also are going to need liverock. The coloring of the picture is difficult to make
Much out, but what is in there will not be sufficient. Until you get a skimmer, you will need to do weekly water changes to keep up with correct water parameters. So after you return the damsel to your lfs, and get more liverock then you will want to wait a few weeks atleast before adding anything alive. Your tank will likely go through another cycle, the length of which will depend on the live rock that you get. Please post a COMPLETE list of the inhabitants of the sw tank. We can't help you if you are not honest with us. As a side note, you should not have any fish in that 75 as it is not cycled. And gouramis can't be kept with oscars. I want to help you, I truly do, as do everyone who has commented on the thread(even if some advice has been given in a rather rough manner). But the only fish out of the stocking list that you provided in different places in the thread that are appropriate would be the ocellaris clown and the yellow watchman. That is it.