Just curious as to what build you have on it...

Plasma I'd make them simple.
arti plasma:
find any VM gas, make into plasma, talth to 15x, crystal to 20x

RP plasma:
find best VM gas, Optimizer to 15x, make plasma.

Proceed to put in 25k cloak(after legion bonus). For arti one, probably metatune+core-tunnel+ergosphere with a couple other artifact based cloaks. For RP, don't waste your limited artifacts(unless you don't have a lot of other good planets to cloak), spend a bit more space and put in NPC drops and researched cloak satellites. Thou you could put in one of the 3 % boosters as that will save quite significant space. Being RP, metatune is probably best choice.

And remaining space however you can max your production ofc. (note adaptive spire is useless on arti plasma so....)

Now, there are more complex way to really max a planet out, like transfuser first and max the ones with ruins/ring only. To uplift all three resources instead of just one. However, I won't bother maxing with plasmas, it's not really "special". I'd rather make a awesome MC oceanic if I were to invest heavily into any one planet.

oops i meant a research plasma - what buildings would you have on it?

i usually have put down 1 Hypernode Brain, about 15 att/def structures in total and the rest i fill with research artifacts or other percentage boost items.

Hypernode Brain Research: 12 Demolish
Hypernode Brain Research: 12 Demolish
Hypernode Brain Research: 12 Demolish
Klorvis Shroud Generator Research: 1, Cloak: 200 Demolish
Klorvis Shroud Generator Research: 1, Cloak: 200 Demolish
Sha'jha Uplink Research: 2, Cloak: 120 Demolish
Sha'jha Uplink Research: 2, Cloak: 120 Demolish
Relay Tower Research: 1, Artifact: 1 Demolish
Refining Lab Mining: 1, Research: 1 Demolish
Warp Gate Mining: 1, Research: 1, Artifact: 1 Demolish
DM79 Datacenter Research: 6 Demolish
Extracted Lithovoric Stem Bonus Mining: 10% Demolish
Sha'din Hyperport Network Research: 3, Defense: 400 Demolish
Interrogation Stronghold Research: 2, Defense: 300 Demolish
Silthion T-Plasma Vesicle Research: 3, Artifact: 1, Cloak: 300 Demolish
Domain Walker Attack: 600, Defense: 600 Demolish
Domain Walker Attack: 600, Defense: 600 Demolish
Dark Null Beacon Defense: 1000, Cloak: 300, Defense: 10% Demolish
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish


I have 4 space left, so I think I'll put 2 Quantum Accelerators on and be done with it.

eh whats with Extracted Lithovoric Stem Bonus Mining: 10%?

think he must mean xecti signal repeater

Also can upgrade the relay tower with a Trellith Comm Relay Upgrade

I won't, save those for arti planets. The refine lab upgrade(the dbl one, not the gift one), can be used on those.
It's also under defended. With the stuff shown, even with 3500+ passive it's only ~20k invasion def after debuff.

Instead, change
Hypernode Brain Research: 12 Demolish
Domain Walker Attack: 600, Defense: 600 Demolish
Domain Walker Attack: 600, Defense: 600 Demolish

To (along with the 4 space)
Meta-Tuned Jammer Size: 1, Research: 2, Cloak: +25%
Chron Shifter Size: 1 Cloak: 300
Chron Shifter Size: 1 Cloak: 300
Ergosphere Filter: Size: 1, Cloak: 150, Cloak Bonus: +20%, Limit: 1
Isolation Bureau Mining: 2, Research: 2, Artifact: 2, Cloak: 400
Resonance Inhibitor: Size:1, Cloak:250, Invasion Defense:500
Resonance Inhibitor: Size:1, Cloak:250, Invasion Defense:500
Adumbrate Station Research: 1, Artifact: 1, Cloak: 200
Adumbrate Station Research: 1, Artifact: 1, Cloak: 200
Akulan Gas Ingestor: Research: 3 Artifact: -2
HyperSensor Satellite Research: 2, Artifact: 2
Quantum Accelerators Research: 2
Quantum Accelerators Research: 2
Inverse-Flux Satellites Cloak: 800

Now, the cost of this change is an ergosphere, 2 chron and a meta-tuned, those being limited stuff. But you will get a super cloaked planet AND 1 more research.
cloak: original 1240, new 2850, assume 3710 passive(fairly easy with just Magnetosphere Charger, mine fot to 3771) it totals to 7800. With 25% and 20% bonus, it's 11700 before legion bonus, 23k-25740 based on legion bonus for most larger legions. For larger legions, you might get to save the chrons by switching it out with a Modified Grid-Pylon, dropping cloak to 24173 at 120% legion bonus. OR switching out a single chron and put in an exotic lab. But saving meta or ergo would be hard without significantly sacrificing production.

I wouldn't make any of those changes, but I have plenty of research already. Yeah, not sure about the Lithovoric Stem, thanks for catching that.

EDIT: Keep in mind, I don't even fully cloak my arti Plasmas at this point, I don't have enough limited % cloak boosts for all of them. Research plasmas aren't worth the bother for me.

I forgot quantum accelerator had cloak....

Anyway instead of the 4 limited artifacts, use Counter-Intelligence Nexus and Modified Grid-Pylon will give an extra 2 research and up to 17k cloak. While Modified Grid-Pylon is also limited, it's usually not on the roster for arti planet cloaking so should be "acceptable loss"
I think 3 extra research and 17k total cloak at the cost of 1200 attack and one grid-pylon should be acceptable. (note there is a total of 1k ID and 200 def added, so the 1200 def from the walkers are covered)

So the final list:
Isolation Bureau Mining: 2, Research: 2, Artifact: 2, Cloak: 400
Resonance Inhibitor: Size:1, Cloak:250, Invasion Defense:500
Resonance Inhibitor: Size:1, Cloak:250, Invasion Defense:500
Adumbrate Station Research: 1, Artifact: 1, Cloak: 200
Adumbrate Station Research: 1, Artifact: 1, Cloak: 200
Akulan Gas Ingestor: Research: 3 Artifact: -2
HyperSensor Satellite Research: 2, Artifact: 2
Quantum Accelerators Research: 2 Cloak 150
Quantum Accelerators Research: 2 Cloak 150
Inverse-Flux Satellites Cloak: 800
Counter-Intelligence Nexus Size:2, Research:2, Cloak:150
Modified Grid-Pylon: +2 Research, +150 Cloak, +200 Defense
Hypernode Brain Research: 12 Demolish
Hypernode Brain Research: 12 Demolish
Klorvis Shroud Generator Research: 1, Cloak: 200 Demolish
Klorvis Shroud Generator Research: 1, Cloak: 200 Demolish
Sha'jha Uplink Research: 2, Cloak: 120 Demolish
Sha'jha Uplink Research: 2, Cloak: 120 Demolish
Relay Tower Research: 1, Artifact: 1 Demolish
Refining Lab Mining: 1, Research: 1 Demolish
Warp Gate Mining: 1, Research: 1, Artifact: 1 Demolish
DM79 Datacenter Research: 6 Demolish
Extracted Lithovoric Stem Bonus Mining: 10% Demolish
Sha'din Hyperport Network Research: 3, Defense: 400 Demolish
Interrogation Stronghold Research: 2, Defense: 300 Demolish
Silthion T-Plasma Vesicle Research: 3, Artifact: 1, Cloak: 300 Demolish
Dark Null Beacon Defense: 1000, Cloak: 300, Defense: 10% Demolish
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish

The RSL Uplinks or whatever they're called are decent for plasmas too. (The ones that use 3 space, give 3 research and some def and cloak)

They're not great structures, but if you've got open space on a plasma, it's the best place to put them.

I got this stuff on my Plasma, and it does have small moons so i put a couple Barrier Nexi for the def:
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish
Affection Disseminator 3.0 Research: 1, Population: 500, Defense: 500 Demolish
DM79 Datacenter Research: 6 Demolish
Interrogation Center Research: 2, Defense: 200 Demolish
Spy Uplink Research: 1, Cloak: 40 Demolish
Spy Uplink Research: 1, Cloak: 40 Demolish
Obviation Barrier Defense: 1200 Demolish
Obviation Barrier Defense: 1200 Demolish
Obviation Barrier Defense: 1200 Demolish
Obviation Barrier Defense: 1200 Demolish
Obviation Barrier Defense: 1200 Demolish
Vaash Holomatrix Research: 2, Cloak: 100 Demolish
Chron Shifter Cloak: 300 Demolish
Chron Shifter Cloak: 300 Demolish
Akulan Gas Ingestor Research: 3 Demolish
Permafrost Sub-Network Research: 1, Population: 50, Cloak: 50 Demolish
Sha'din Grid Network Research: 2 Demolish
Barrier Nexus Artifact: 1, Defense: 300, Defense: 20% Demolish
Barrier Nexus Artifact: 1, Defense: 300, Defense: 20% Demolish
Dark Pylon Shifter Defense: 400, Cloak: 90 Demolish
Domain Walker Attack: 600, Defense: 600 Demolish
Silthion Gas Vesicle Research: 2, Cloak: 150 Demolish
Lazuli Pylon Invasion Defense: 600 Demolish
Lazuli Pylon Invasion Defense: 600 Demolish
Hypernode Brain Research: 12 Demolish
Hypernode Brain Research: 12 Demolish
Hypernode Brain Research: 12 Demolish