# Established tank with PFS, looking for new substrate



## jestes (Feb 13, 2011)

Guys, I'm trying to decide what I want to do here. I've got a 55 gallon with PFS as my substrate right now, but I'm having trouble growing my dwarf hairgrass. I do EI dosing, and have 2X54 T5HO over top of it. The DH will grow, but not nearly as fast as I'd like. Root tabs seem to help, but I can see that getting expensive before too long. I'm thinking about switching to ADA Amazonia, since it's already got ferts and such in it. I have two questions though:

Is it worth it? In other words, will I have better luck growing plants in it than sand, or am I doing something wrong in the sand?

If I continue EI dosing after adding Amazonia, will the dosing keep the substrate rich enough to support swords and such?

Thanks!!


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## Diana K (Dec 20, 2007)

You are not doing anything wrong with the sand. 
Sand has not cationic exchange capacity. It has no way to hold fertilizers. 

Switch to any of several materials that have a good CEC and the plants will do a lot better. The water column dosing will work its way into the substrate, and the substrate will hold onto the nutrients in a way that the plants can use. This is a much more stable supply of nutrients for the plants, and some plants seem to prefer getting certain nutrients out of the soil, through their roots.


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