[dwarf red gularis killifish fry help]

So I have a breeding pair in a blackwater tank with lots of salvinia. I took some salvinia out and put it in my shrimp tank because I had to much in my killi tank. About a week later or so I see 30+ fry. So the shrimp tank is hard water and my breeding tank is soft water, what should I do? I've had them in my shrimp tank for coming on 2 weeks and I'm not sure if I should grow them up some before trying to slowly acclimate them to a blackwater set-up or what. I don't want to stress the fry out, they are literally just 2 eyes and a stomach floating around still. Seemingly none have passed and all seem to be doing fine. Any one have experience with fry being born in an extremely different pH then what they should be in?

[Algae identification.]

I just bought a rotala rotundifolia plant and I noticed that it had this algae on it. What type of algae is it? Will it spread if I don't remove it? If it causes more algae should I just snip it or do a peroxide wipe?

[Lemon tetras different.]

Thanks for the reply. I do believe you are correct. I went to another LFS and got some lemon tetras but they aren't colored up, will this come in time when they feel more secure? they are larger then my actual lemon tetras.

[Lemon tetras different.]

Here are my actual photos of the 2 different types. The pictures with 2 of them are the plain ones. the single one is the the more lemony types I got.

[Lemon tetras different.]

I recently got lemon tetras from Petco. I bought 8, 6 from one tank 2 form another. The 2 from the 2nd tank were the normal yellow fish with red eyes. The 6 from the other tank were smaller, probably younger, but had silver color and normal eyes. I've seen them both ways from watching videos and am not sure what is up. Are the not colored up ones juveniles or possibly females? The first image is going to be a not so helpful picture of what I'm referring to, I'll post 2 others from the internet to show what I am talking about with the differences. Thank you for any help!