A lid set i designed in tinkercad.

This will fit your standard size mason jars and also jam jar for the top.

This design uses the kratky style hydroponics method.

Design is pretty straight forward, you can either glue the two lids on top of each other as shown in the picture, or use 4x m3 x 8 stainless steel screws to hold them in place. The holes are already set for the m3's so its just a matter of screwing them in.

These take rapid rooter and/or aerogarden sponges/plugs.

Setup is easy. Fill the large jar with nutrient solution, screw on the lid with the sponge installed. Place your seeds inside the sponge (typically in the hole that is designed into most of the sponges available). Screw on a jam jar on top to act as the humidity dome for the first week or so.

Cover the large jar with either a sock (easy to rewash and reuse) or foil, paper, etc etc. You can even spray paint the jar itself black.

I prefer the sock as it makes it easier to look on the root structures and water/nutrient level for when its time to refill.

The jar has to be covered as light hitting the nutrient and roots will create algea which will kill your plant.

Once your leaves have sprouted you can take off the jam jar (humidity dome) and use it to start others or wash and use it for something else.

Thats basically it, you don't need to change water out or have an air pump or anything of that nature.

If you want it to go faster a plant heat pad under the jars for the first week or so will help promote sprouting.