Cation Exchange Capacity?

[Scapexghost]

I understand the science behind cation exchange and how it plays into agriculture but I don't quite understand how it plays into aquariums. More accurately, I don't understand how important it is. Some people make it seem like one of the most important aspects of a planted tank while others don't mention it at all. I don't recall cory ever mention it, he probably has in some live stream but he certainly doesn't put much emphasis in it. I assume it's because Cory doesn't want to overwhelm people and scare them away from planted tanks. Cory also endorses inert gravel substrates, which have no CEC, so I assume he doesn't see CEC as important.

So, can anyone give me a quick run down on CEC? How it plays into aquatic plants, if i should care about it, how to improve it, etc.

[Fish Folk]

Here’s a very fun non-technical article on CEC by Scott Fellman.

Sounds like his review in standard CEC measurement units goes:

Sand = ca. 1

Clay = ca. 30+

Zeolites = ca. 100

Soils / Humus = 250

I think at this point it’s helpful to learn  what the folks over at Green Aqua do when building soils / substrates…

Now, I’d also like to call out @Streetwise who has worked with  Walstad method tanks awhile and is in a better position to reflect on your question from experience. 

 

[Patrick_G]

I’ve sent off garden soil for testing, it’s actually pretty inexpensive. It would be interesting to learn the CEC capacity of some the commercial and DIY substrates. And of course the results would include a full report on the nutrients also.

The crew at green aqua produce some spectacular tanks, it’s hard to argue with results, but there’s certainly more than one way achieve good results.