Aquarium Sponge Filter Setup

These are 4, 10 gallon fish tanks I got most of them for around $8.00 each at thrift stores, One had a crack on the bottom which I repaired with silicone and another one had severe calcium buildup which I was able to clean up with vinegar, each tank has a two sponge filter coming in at $3.00 A piece, all are connected to a 40 gallon air pump that cost $15.00, The airline tube suction cups and  Air release valve's we're only a few bucks, I got the light from a Chinese dollar store for $7.00 and the plants are Pothos,Java Moss, Water Wisteria, Pygmy Chain Sword, Cardamine Lyrata and Brazilian Penny Wort, I got a lot of the plants on eBay for cheap, the sand is pool sand, this probably won't be the last you'll see of my aquarium set up as I have plans to improve it much more and an idea for an experiment, consider this phase 1.