When I first started I used what ever was on hand. This included chair backs. I then bought a lab stand which served me well for quite a while, or at least until I started trying 3 valve setups. I later invested in 2020 aluminum extrusion. 4040 is also a good option.
Reservoir / Water Bottles
For a long time I used drink bottles, especially bottles from sport drinks that had nipple style top. I then moved to lab squirty bottles which I bought from the same place I got the retort stand. Later, when I upgraded the stand to 2020 extrusion I started using the T33 filter holders.
The lab squirty bottle has a tube that runs through the lid and this makes it easy to turn them in to a Mariotte syphon. A Mariotte syphon delivers a constant rate of flow regardless of the liquid level inside the bottle.
I remove the top tube and then I make a small hole at the bottom and hot glue a piece of stiff tube in the hole. This then allows PVC tube to be attached.
T33 Filter holders are very popular and used by some of the commercial systems. A benefit of these is they have threaded connections so nozzles can be easily attached.
Any soft plastic tubing will suffice. I buy clear PVC aquarium tubing from the local pet fish shop. The most common sizes are 6mm and 10mm but it depends on the size of the nozzles you are using.
Almost anything can be used as the splash tray/container. I have used many different things; glass bowls, the outer cover from CD containers (the 50 stack size), cups, soy sauce trays, baking trays. Black baking trays work very well. The black colour with water acts as a very good mirror and gives excellent reflections of collisions.
After I became more serious with water drop photography I had a couple of acrylic trays made. One is 80x40cm and the other is 60x30cm. I also bought black and white acrylic sheets to use as inserts.
Bottle Reservoir Additives: Thickener
Plain water is OK when you are first starting but if you want to achieve complex shapes you need to use something a little thicker. For beginners I suggest milk; full cream and chilled. From there most people start experimenting with adding thickening agents to water. The most popular additives are Guar Gum (my usual choice) and Xanthan gum. Glycerin also gets mentioned online but I have never tried it. Both Guar gum and Xanthan gum are common food additives and safe to use.
I mix a level teaspoon of Guan Gum powder to 1 litre of warm water. I blend this is an electric blender and then strain with muslin cloth to remove any bits. This gives me a slightly cloudy thick liquid which I dilute with cold water and add colour as I use it.
Bottle Reservoir Additives: Colouring
Splash Tray Additives
You can get by with using just water but adding a little bit of detergent can have a big influence. The Worthington Jet can become much taller and thinner.
To the water in the splash tray I add various detergents or cleaning fluids (I have tried lots of different ones). One that works well is natureclean’s All Purpose Cleaning Lotion. This works very well and was recommended by Corrie White sometime ago.
I now use single voltage power supplies; either 12V or more commonly these days 24V.
Make sure you use a PSU that is able to supply a decent current. Most valves require around 0.2 to 0.275 amps each. I tend to error on the side of caution and the ones I use are rated around 5 Amps.