Hikari makes a good food called "First Bites". It's better for livebearer fry than egglayers so right up your alley.
As the fry grow, there is another food by Hikari called "Tropical Fancy Guppy". That is better food for growth, conditioning and breeding. It should be used in addition to other foods like frozen baby brine shrimp, spirulina flakes, blackworm flakes. ) Northfin also makes a fry food but I don't believe it comes in smaller sizes so also a bit expensive.
You don't want to keep any of the glo tetras with the male Guppy as they will chew his tail.
I think the plastic thing you are describing is a guppy breeder box and truthfully, just because you put it in the tank, the fry may not go into it. They are also better off with more space than less. With good foods they will grow quickly so you won't need to use the mag glass for long.I am new to breeding So i have this question.Hikari makes a good food called "First Bites". It's better for livebearer fry than egglayers so right up your alley.
Another good choice is Dr. Bassleer Biofish food baby nano. It's a protein packed food for growth but it is a bit expensive. ( Good food ain't cheap.
As for feeding, baby fish need more feedings than adult fish so at least 2-3 times per day. Look at their bellies before you feed. If they are round, they don't need feeding. If they are flat, they need feeding.
I would not feed pellets to Guppy fry unless you crush them into a powder first. In a pinch, you can crush regular flake food into a powder but adult foods are more for sustaining life not good growth so they should not be the main food fed to fry.
Lastly, fry foods are going to make the water foul if you over feed ( and you will over feed because there is no standard amount to feed ) so you should be doing water changes on fry tanks at least 2 times per week ( especially in a 6.5 tank. )
If you put a lot of frilly plants in the 40, they can all go together but there is the possibility that some of the fry will be eaten. When breeding Guppies, if you place 2 or 3 females in with the male in the 6.5 gallon tank for a week, they all will most likely be impregnated. You can remove the male into another tank with 2 or 3 other females for another 2-3 weeks , so he can get some strength back and impregnate the other females. At that point you have a choice: A) move the male into a separate tank by himself. B) Use a divider in the 40 long and place him on one side and the existing fry on the other side. C) Place the females on one side of the divider and the fry on the other and when the females give birth, move the fry to the other side of the divider and leave the male in the 6.5. D) Leave the females in the 6.5s until they give birth then move the fry into the 40 and leave the females in the 6.5s. ( You just have to do one of these. ) With female Guppies, it's more hazardous to move the females the further into their pregnancy they get so you either leave them be for the duration or you move them soon after impregnation.
Look for Java Moss and/ or Guppy Grass plants. They are both easy to care for and frilly.
If he doesn't have any issues during that 30 days, you can add him to the 40. If he has any issues during that 30 days, the 30 days starts again from the time the issue is resolved.
