end cap, 1M flat bottom marley flowline guttering (better than hunter squareflow), gutter drain end. Make 12 of them. (I run 11 due to a ventilation duct in the way of number 12) Do not mix and match gutter types on 1 length or you will get leaks.
place three, one above the other on a wall and run a square downpipe from the top gutter end, into the middle gutter end below. then from the middle to the bottom one, fit a 45 then downpipe to go back to your tank. That is one wall.
Four of those in a square, 3 x 600W sodium hanging in the centre in cooltubes.
22mm pipe from tank to Grundfos Alpha 2l pump on floor. 22mm pipe to halfway up the wall where second pump is. 22mm pipe to ceiling T. run 22mm pipe in square around top. 15mm pipes running down from corners with 2 x T and 1 elbow positioned at the gutters with red handled stopcock valves on, (15mmT, 15mmpipe, valve, 15mm pipe, corner, pipe outlet)then a 15mm corner to drop into the gutter. Individual taps lets you make all outlets flow the same.
Now water is pulled into the first pump, up to the second, then to all four 15mm downpipes where the same flow enters each gutter, runs along then waterfalls down the downpipe, gutter end combo to the tank.
Get some of that tray topper stuff with the square tubes in it and cut some gutter tops, then some holes for your babies to be put into. Also some holes for the square downpipe and the 15mm inlet pipe. Cable tie them down.
For a more scroglike colosseum, get some wire based garden fencing, the green stuff with rectangular holes, then cut the rectangles into squares with some tin snips, the standard holes are just a bit small. Hang 4 sheets of that about 25cm from the gutter front to support your plants, which will want to pull themselves out of the gutter.
On week 3 of flower, check for roots growing into the main tank and whether they will flow towards your pump inlet. If they will, trim them often.
With my clone, I need 9-12 days veg, 60-64 days flower. More veg time than that and the roots outgrow the guttering and you get leaks and runaway humidity. You may find it takes a couple of cycles before you find the best method for your particular plant in this system. I would not recommend changing plants often because of this but to find a good mother instead to take clones from and get used to the system.
I just run a chiller to keep the roots the right temp, I highly recommend one.
Also, a small rootball in the right environment will produce more than a large rootball in the wrong one. Concentrate on your environment and the roots will just happen. If you think you need root stimulants and boosters, what you actually need is to look at your environment and see what is wrong.
Any questions just ask