Platy Fry: How to help them survive?

Hi all.

Four days ago I noticed about 10 tiny platy fry hiding in the hornwort plant in my 28 gallon freshwater tank.

Here's what I've done so far but if anyone has any good advice, please let me know:

Put a bit of nylon over the bottom of my powerfilter with rubberband to ensure the platy fry don't get sucked up into the filter box.

Bought and installed a tank divider that separates my 3 catfish, 5 mickey platies and 2 zebra danio from the platy fry still very tiny, hiding out in the hornwort plant.

Bought baby brine shrimp (frozen cubes) and liquid fry food.

Did 1 water change of only 3 gallons today.

What else can I do to ensure the platy frys are going to continue to grow and not be eaten by any of my other fish?

The tank divider I bought is not wide enough - there is a 1 inch gap that my catfish and zebra danios fit through, but so far the mickey platies have not tried to infiltrate it.

I also cant find any info. on the internet about how long it takes platy fry to grow to a point where they are too big to be eaten and when I could take out the tank divider (will that really help them feel more safe do you think?).

Any advice is really helpful. I had no idea my platies were pregnant. May have been when I bought them from Petsmart.

now my filter is acting up with the nylon on it

I have a 30 gallon aqua clear filter that I stretched a piece of panty-hose nylon to the end of with rubberbands to ensure that the platy fry I have won't get sucked up into the filter. But the darn thing won't let water through for circulation at the top of the tank.

I'm afraid if I take off the nylon the platy will all get sucked up into the filter. But what are my other options? A mesh bag to rubberband at the end? Won't the holes in the mesh bag be too big for the fry to prevent them from getting sucked through?

Also, I returned the tank divider b/c the holes were large enough for the platy fry to swim through. Instead, i just bought another bushy hornwort plant, which I put along side the other hornwort. It's really thick and tall so that should keep them well hidden.

But this stupid filter thing is driving me crazy. What can I do to the filter's end as far as covering it since the pantyhose nylon is too thick apparently, and not enough water is getting through.

Help!