Hi
@macka09
The Phanteks p400a doesn't offer many options for radiators. You can install a maximum of one 360 in the front and one 120 on the back. For the one in the front you will have to remove the hard drive cage, according to the manufacturer. It is not specified how strong it can be, you have to measure whether you have space for a 30mm or 45mm thick radiator. For the components you want (Ryzen 5000 and RTX 3080) I would already see that you install a 360 45mm in the front and a 120 on the back. Since the 3080 alone probably needs the 360 for cooling, because of the high TDP. Then theoretically the 120 would be for the CPU. If both are now running on load, it can still be easy that the temperatures are not exactly cool. That also has to do with the fans and their speed.
I'll link the components.
I would use this set as a basis.
Mit den neuen Eissturmsets erhalten Sie alle Komponenten die Sie für den Start in die Welt der Wasserkühlung benötigen. Die Sets richten sich dabei nicht nur an Einsteiger sondern auch an Profis. Alle verwendeten Komponenten sind optimal...
www.alphacool.com
In addition a 120 radiator, either the 30mm or the 45mm thick for the back, you have to measure how the space is enough.
The 30mm
The 45mm
You don't really need anything else, apart from the cooling block for your graphics card. The set includes 8 straight and 2 angled connections, you need 2 for each component. The 1 liter of coolant should be enough, if it is not quite enough you can fill it up with distilled water. 3 meters of hose are also included, that should be more than enough.
It could also be that the tube of the equalization / pump combination is too high for the housing. Therefore, I am also linking a shorter tube, which you can easily replace if it comes to the case.
I hope I could answer your questions. If not or you still have questions, just get in touch.
Best Regards