Originally Posted by NativeCreations
My mistake, the FloraMax being lava rock does not have a high CEC but has lots of small pores that can hold nutrients and such. Something more clay based like Eco-Complete or stratum would have a higher cec. Would one of those two be easier on my plants at planting than straight FloraMax? what's your opinion on layering substates?
My opinion on layering substrates is no. Too much mess, too much mixing, too much hassle, too much money. Spend the time / effort and money elsewhere on your tank.
Eco-Complete is lava rock = no CEC. Big pores in the floramax = no CEC.
CEC requires bonding sites on the particles themselves. More surface area = more CEC capability. Clay / organic matter has lots of bonding sites, while sand has less, and large gravel particles such as Eco-complete or FloraMax will have have very little CEC.
Now, active substrates such as Stratum or ADA aqua soil are made from organic matter, and will have a high CEC. But, they are active and buffer the water (pH goes down as the substrates uptakes kH
- Carbonates). They are best suited to be used with gH
water only, so as to prolong their buffering ability.
I say stick with what you have, but supply the plants with nutrients via the water column and via Osmocote+ tabs.