Update 2024-08-11:
The pictures aren't quite up to date but no parts on the pictures are changed.

I added a waterbox (which due to the immense size I couldn't print without warping issues so I put a waterbucket inside).

And 2 types of sealings, for the inside of the round connectors and for the socket / base plate.
https://www.tinkercad.com/things/11Lyt0vOLlR-roundconnectorsealing?sharecode=N7ShEuEJ9QqOALwidh6Qgoze547cXw-G-0jEpUT9KoA

https://www.tinkercad.com/things/bXfO3pinBA3-roundsealingsocketbaseplate?sharecode=cRxWluHd36OIeKVQAjZQ6z0YvPwRcwVih6R9vb2_0fM

For the tpu I used the settings I used for the peli case inlay, if you have trouble to print them take a look.
https://www.thingiverse.com/thing:6705889

I used a 5 Liter water bucket and cut of some of the edges and pressed it inside (everything is pretty stable now).
(the cheapest available for 3.50€)
https://amzn.eu/d/6rf4yZ2

(at least I don't have to worry about water leaking by using a reliable solutiuon while improving stability)

I created a own version of a led stand as addon for https://www.thingiverse.com/thing:4869304 which seems to be a remix of several other versions which seem to be compatible (I am confused.).

following parts were additionally bought:
pump:
https://amzn.eu/d/elbNr3v
led:
https://amzn.eu/d/iM129su
trafo for led:
https://amzn.eu/d/580gJXN

additional stuff:
for easier starting and transplanting:
https://amzn.eu/d/dfeuKgB

reason: other versions were based on led bars and so on and I wanted something more customizeable like for plant LED Band's.

They usually need a smaller distance and can be energy saving compared to other solutions (like 100 Watt Bars on each side).

Anyway I created a common adapter system which you can also use as system to connect other things to the socket holes or whatever.

Printtime at all: I don't want to talk about it, tried many designs and petg can be a beast. this project ripped 1 heatbed, 2 extruders, several nozzles and kilograms of petg.

Socket
https://www.tinkercad.com/things/gw2GhSLM5VD-finalsocket?sharecode=B1sVHLgKc0JreZHxoZyP__XTDFc-djOz-sO9mRxRgpg
Printtime: around a day

Round Connector (For a 5m LED Cable and 3 arms you need atleast 12 of these)
Printtime: around 1.5 hours
https://www.tinkercad.com/things/ddzGSG6PK3g-finalroundconnector?sharecode=AtuwNe1fIGtNgjuP7ptKtZ4i5CeTI-lnZa0zMKTfRFw

LED Stand (Round Spiral thing with place for a LED Band to glue or fix it however to it and give control to the led band shape, for 3 arms and a 5 m led cable you need at least 9 of these)
https://www.tinkercad.com/things/6Zp2t4IRitu-finalledstand?sharecode=g-A-ffppaGPb6Mgto6A-YUHx3rNoC9Oax1C5jwYCBg0
Printtime: around 4 hours each

Arm or Connector for LED Spiral's:
https://www.tinkercad.com/things/01fz0KT183X-connectorforbaseplatefinal?sharecode=dP6ocAFV0Ori2bWfkDFxCAzZlt5psvNDZqxi5gdX7EQ
Printtime: around 2.5 hours each ( I used 3, more could be better but than you need to scale up the amount of other parts as well)

Bucket (not necessary, I still need to print it myself but should fit.):
Volume was around 1 liter
https://www.tinkercad.com/things/283gcqzc9xb-waterbucketforhydroledaddon?sharecode=EWBX7HPNP4D_3F0Oq9sIn2dO_Qg5-MapKJd9h0qm1YA
Printtime: around a day