Nate. Welcome to the forum and all but please stop trying to be a smarty pants because you are just embarrassing yourself [emoji21]
The thread is about melting SWORD plants. After you assumed I didn't know what liquid co2 was I stated that I have no issues with using glut with swords and posted a picture to back up my claims, you take the hump and think we are in a tank contest then proceed to post a picture of a tank that doesn't even have any swords in it. I then post a picture of swords thriving with just liquid co2 and a soil substrate (relevant because of high microbial activity producing some amount of co2) than you post a link for my benefit about co2 [emoji23]
Op the liquid co2 is fine for sword plants.
I don't know how it works exactly but there are two reasons I can think why swords would melt AFTER adding liquid co2 and those are the nutrient demand increase is no longer being met (you already figured this one) or the plants are investing their energy in to producing newer leaves with less rubisco as it is no longer required in large amounts. Co2 sources need to be consistent and stable for the plants to adapt.
This is why plants melt when first submerged. They need to produce new leaves with a thinner boundary layer and with leaves with a new rubisco content that reflects the current co2 levels in the water. If the co2 is sporadic and unstable the plants will be forever investing their energy sources in to rubisco production which means old leaves melt. This can cause algae simply because of the increase in decaying organics/unhealthy plants. Good thing about glut/liquid co2 is that it destroys algae too.
If it isn't overdosed glut is an effective means of co2 but no where near as efficient as the gas carbon dioxide directly infused in to the water. Many many people run liquid or glut only tanks with success. The bigger the tank and the more plants you have this option becomes increasing unviable due to cost.
what is this magical gas you speak of
jk jk