High Ellie, good to see the babies are coming through OK and playing the game.
When I first started breeding bristlies, they spawned in a 3ftr- thankfully I had my old 2ftx1ftx1ft laying around , so the first 2 consecutive spawns went in there, mind you a 2ftr gets pretty grubby with 150 babies in it- I'd reccomend vacumming every weekend and 2-3 40% water changes a week.
Or if you can afford the space you could go with my personal favourite:
3ftx15inchx20inch tall( approx 120-130 liters), these are great sized tanks for growing out young and bit easier to maintain.
As for cleaning your tank- why? let the baby fish do it for you.