When you use a nutrient high substrate and it is used up, Do you have to replace the whole thing every several months or what?
I have un-coated small grave that I added some Ecco complete ( about 3cps). I have Crinum that are very heavy root feeders and are not doing well. My Tiger lotus is doing ok so I assume that the Crinum is missing something. I have not read here to use root tabs, so what do you use on these type of plants with no CO2. If the Ecco looses its nutrients it sounds like a pain to have to replace it. I like the small gravel look more then the Ecco. So far I have not tried to grow stem plants which I also assume needs more nutrients at their roots.

Well, most things such as Delta mud clays, ADA aqua soil will last several years, and I'd not worry much over the long term unless you keep everything running for more than 10 years. Even there, you can add more without a tank breakdown.

EC has no nutrients to speak of, it's just volcanic pumic with some extra iron is all.
It might be some exchange sites for nutrients etc, but it itself has no source like the other two mentioned above.

If you read the non CO2 method here, I suggest another way to do this, and also suggest that you can use sediment ferts as well(best to use both methods).


Regards,
Tom Barr

Maybe I am dense or missed it. Below you say use "sediment ferts" but what I read in "non CO2" did not explain what sediment ferts are. Are we talking soil/leonardite, what?

Stem plants get the majority of their nutrients from the water column, and don't require any special substrate. Roots are more of an anchoring method more than they are necessary for nutrient absorption.

I have trouble with Crinum. It does not grow or die completely. I was guessing that it was a heavy root feeder. I tried grow tabs but they melted so fast my water was a cloudy mess.
I thought to add something to the substrate without changing the look of the small gravel I like. But if the nutrients deplete in a year or less the ratio of gravel to this added substrate would become uneven in appearance as I would have to add more.