| | Re: DIY carbon source, not CO2
Yes, potassium glutamate is akin to sodium glutamate which we eat all the time in flavored chips. All the chemicals I listed are human consumable, easy to get on Amazon. Of course you can overdose these chemicals like any.
Both AminoButyric Acid & glutamic acid have an ammonia molecule attached to the carbon chain. I guess it's good if your plants need Nitrogen.