German Blue Rams

After loosing my puffers a couple weeks back I had an empty tank. I did a water change and put a couple test fish in (along with 2 chunks of drift wood and 4 large plants more rocks etc). One fish is black shark that my lfs gave me. I know I will be moving him to a bigger tank pretty soon. He's doing great. The other fish is a fresh water flounder which I was told specifically was fw only- (not true BTW it is brackish) so I will be moving him to my brackish tank after a couple more weeks of quarantine. I was told to add melafix/pimafix as a precaution to the new fish so I have been doing it daily. I am running a HOB and a sponge with a power head. I also have been using- Mardel living nitrifying bacteria and enzymes daily (since I thought I may have killed off the good bacteria in the puffer tank). I also took fresh used HOB filter media out of our Zebra Cichlid tank to help jump start the tank redo when I did my last water change.

I had these two in my 20 gallon for about a week and everyone looks good. I added the dither fish (5 small solid black emporer tetras) on Monday and then last night I added 4 German Blue Rams (3 females and 1 male) the Rams were 50% off resulting in $5.98 each <<<so I couldn't pass them up>>>. Everyone seems happy. I think the Rams have paired up all ready. The male only allows one particular female to swim in his spot which is right in the front of the aquarium . So the other 2 females end up hanging out in the back.

My question is will he mate either of them or should I get another smaller aquarium and another male? My neighbor has a male that is 4 months older than mine so I may be able to give her one of the extra females. I really like these fish they are very beautiful.... The shark I swear is in love with the new male and female pair- he hangs out with them (probably waiting for them to lay eggs) but right now they look like buddies.

My water is as follows;

82-84 F
low nitrate/nitrite
100ish hardness
160 alkalinity
6.5-6.8 PH

They are eating well dry & frozen. I plan on doing a 30% water change on Saturday btw.

Thx- Julie

Not a professional on rams but I would leave all three females as bet the male will take turns and that will give the female he's in love with a little rest after spawning.
Agree the shark would love to have fresh eggs to eat. lol