Will the female opaline hurt the dwarf gourami males when she is bigger?

I currently have a 20 gallon tank with 7 neon and cardinal tetras ( mixed school) 6 growth stunted male guppies (they are really small.. and I’ve had them over a year so I know they aren’t young) 3 male dwarf gouramis and a female opaline gourami. They all get along for the most part.. although there is one who seems to be a bit more dominant.. will the female opaline hurt the dwarf gourami males when she is bigger? (She’s maybe 3” right now)Also can dwarf gouramis and opaline gouramis mate?

 

I'm no expert but I'd say your a little overstocked. Not to mention DG can be very aggressive with each other and any other species. Especially males. I'd be more concerned with them hurting everything else and each other.

 

It is overstocked IMO. Usually you do not want to mix gourami species and only have a single specimen in smaller tanks. The opaline gourami will attain a good 5in while the dwarfs stay around 2-3in, but I'd expect the males to begin fighting over time. Also, 20gal is the minimum for opalines, and that means minimum as in no other or very few fish with them. Adult opalines are known to eat small fish (neons, cardinals and guppies).

The gouramis could crossbreed (doubt that will happen though) but you don't want that to happen as the male will bully all the others away from his nesting area. Also, it would be rather hard for a small male dwarf to spawn a mature opaline female.

 

It is overstocked IMO. Usually you do not want to mix gourami species and only have a single specimen in smaller tanks. The opaline gourami will attain a good 5in while the dwarfs stay around 2-3in, but I'd expect the males to begin fighting over time. Also, 20gal is the minimum for opalines, and that means minimum as in no other or very few fish with them. Adult opalines are known to eat small fish (neons, cardinals and guppies).

The gouramis could crossbreed (doubt that will happen though) but you don't want that to happen as the male will bully all the others away from his nesting area. Also, it would be rather hard for a small male dwarf to spawn a mature opaline female.

What should I do about it being overstocked? Will I have to get rid of all my other fish for the opaline?

 

What do you want to keep more? Once you decide that we can help you out. Upgrading your tank could also help but like Demeter said, the Male DG may cross breed with the opaline.