[jcoulter]

Recently came across a post that some plants are a "C4 plant" and thus require sodium. The poster said they add sodium bicarbonate to their RO water.

Dwarf hairgrass is apparently one of these plants and I have a lot of in my tank so I'm interested in finding out more.

Can anyone elaborate? Do you dose sodium? I generally haven't seen mention of sodium in the 'Share' thread, but I've also not read the whole thing.

 

[Surf]

I wrote that. On the share your dose thread most of those people use TAP water. Tap water can have 1 to 20ppm or more of sodium. Also many use nutrient rich substrates which likely have sodium . In my case I use RO water with a TDS of 1ppm and an inert substrate. So my tank typically has no sodium. When I added Dwarf Hair gas it didn't grow and didn't die. Other plants were growing very well. However once I learned it was a C4 plant I added sodium bicarbonate to maintain a sodium level of 2ppm. Now it grows.

Most plants in the world are C3 plants and they don't need Sodium to grow. And with most water having some sodium most people would never notice this. However C4 plants do need it as a micronutrient. These are link about C4 plants and a list of plant groups that are C4 Eleocharis is listed a C4 plant group and dwarf hair grass is a member of that group. And I just noticed Anacharis, another aquarium plant is on that list.

http://https://en.wikipedia.org/wiki/C4_carbon_fixation

https://en.wikipedia.org/wiki/List_of_C4_plants

https://en.wikipedia.org/wiki/Eleocharis

https://en.wikipedia.org/wiki/Egeria_densa