If you have got all the way to Step#52 with me, then you'll have realised that being green often means finding slightly different, more mindful ways to do things - including having fun.
Swapping single-use plastic water balloons for the cute, crochet variety has allowed us to continue to have garden water fights without adding to microplastics in the environment (and without the balloon-choking risk to animals and babies posed by discarded plastic water balloons).
This free online pattern (from the 'Left in Knots' website), found by scrolling to the bottom of their page, is clear and straightforward. But it is an American crochet pattern, so you need to add an extra crochet stitch; where you see SC in the above pattern do DC (double crochet) and where you see DC in the above pattern do TR (treble crochet). This difference is because British crochet notation refers to the number of loops you have on the hook, whereas American crochet notation refers to the number of times you move the hook to complete the stitch.
You will need approximately 12g of Chennille Chunky Baby Pram crochet wool per water balloon - this soft and absorbent wool makes the best - biggest (10cm x 8cm) and wettest - balloons.
If you haven't got the crochet skills yourself (I haven't) then ask around to find a crafty soul to help you out - thank goodness for talented relatives!
The Clever Cactus in south-east England sells reusable crochet water balloons. As do a number of British-based-makers on Folksy. There are also some reusable water balloons on Etsy, but many are based in Canada or the USA (so double check the seller location before you order!)
A note on practicalities - you do need to spend time hunting around to find the reusable water balloons after you have finished your water fight, and you must rinse the reusable water balloons after a day of use (i.e. swish them in a bucket of clean water to remove soil / sand etc and squeeze them out) and hang them up to dry. A £3 PRESSA hanging dryer from IKEA makes this very easy.
Preparing for the water fight is much easier however - just put the crochet balloons into a bucket of water and then fish one out and throw it! Running back to the bucket(s) to re-dunk them after a couple of throws adds a new dimension to the game.
In this instance, the eco way of doing something is actually MORE fun. Hurrah!