Madsen and Cedergreen 2003 and Jackson et al 1993

Tom Barr

Staff member
Jan 23, 2005
Several folks in the past have suggested that sediment based nutrients are preferred for aquatic macrophytes.

However, two research papers suggest otherwise.
This one I recently ran across:


The Madseon/cedergreen paper I've known about for several years now.
Essentially suggesting that aquatic plants in general prefer any location as long as there is enough nutrient to prevent limitations.

They are opportunistic.

K+ is about the only nutrient that's really water column demanding and NH4 is about the main one we can keep in the sediment and have decent growth without affecting the fish too much.

Small amounts, dosed daily, or at very low continuous levels of NH4 especially at lower light, can and do work.

But aquarists muddle that up, and can do as much damage with that as with CO2 in the water column.

If you are no good with the water column. often using sediment is wise.
So you might tend to believe that nutrient rich sediments are the way to success, rather than water column dosing.

However, that's one sided and you never addressed the mistakes you made with the water column.

It's not the method's fault, it was your own.
Many take personal offense to this, but it is true.

I made the same types of assumptions and never got far either.
Now I can look back and laugh at it and see why each method works and explain why, test it, show why, and show cause.

Understanding why and how each method works and relates to the other is important in order to address why various methods that appear different, are really not so different after all.

We have many different methods that work in this hobby, not surprising to me, but very frustrating to hobbyists trying to get a grip and have a nice planted tank. Who is right? Which method really works with all these folks saying very different things?

I think understanding each of the different methods is a wiser approach than merely trying to sway a hobbyists/newbie to your one , maybe 2 ways of doing things/methods.

They need more information to decide what method is right for them than just one or two methods.

Tom Barr