Life expectancy of a Root Monster

[GaspingGurami]

Does anyone know how long one of these cones last under the gravel? They have around the same colour and size as my gravel and I can't seem to remember where I have buried them to see if I need to replenish them.

Would one cone be sufficient for an E. oriental of 8" leaves every 6 months?

[Plantbrain]

Yea, once every 6 months is likely fine.
Substrates play a role when the water column becomes limited, other wise the plant will take it from the water column.
Basically the substrate is aback up, some folks rely more on it than others.

But most all plants will take their nutrients through their leaves first, then secondarily through the roots. There is also not much draw through roots in Aquatic plants, if they lived above water then evapotranspiration pulls the nutrients up and out of the roots with a very large pressure.

I hear many say "such and such plant prefers root uptake" this is simply not true.
Some plants will do well with substrate dosing only, but they will do as well and generally better if the nutrients are supplied to the water column.

Swords and Crypts often fall into this group.

I assure you my swords get out of hand with no substrate fertilizers and a decent supply from the water column.

They become a "few month plant" because they out grow the tanks.


Regards,
Tom Barr

[GaspingGurami]

[quote:ec6ba89d47="Plantbrain"]They become a "few month plant" because they out grow the tanks.
Regards,
Tom Barr[/quote:ec6ba89d47]

I know what you mean. I got an Echinodorus oriental that was a 2" plantlet some months back. I thought that the small tank size might miniaturize it. Wrong. It split in two, and together they take up 2-thirds of my tank, one with leaves coming beyond the water level and then melting. So I started trimming each leaf tip that exceeds the waterline.

After a few weeks of snipping off the tips, this plant started to put out flower stalks. I left one stalk above the water and forced one under to see just what happens.... Then, (curiosity kills the cat) the plant slowed and stopped bubbling while the other E. oriental (slightly smaller) showed no sign of slowing down in bubbling.

Then both started to grow pale white new leaves, and later the bigger plant's new leaf started to grow deformed, while the smaller stopped bubbling too. Thinking it is Ca/Mg blocking, I changed water and things have more or less gone back to an even keel except the bigger oriental which seem to have become dormant.

Now it never blows any bubble, and other than growing some plantlet at the immersed flower shoot, the plant seems to be wasting away, melting at the edges, main veins turning reddish brown, all these on the older leaves. Young, pink leaves have greyish spots. It also look like it is splitting up into 2 plants. What's amiss?

I've been told by many LFS that it is a sign of base fert exhaustion. I have been putting away the prospect of re-doing my basefert in hopes that liquid ferts are enough to take over.

Light: 13wpg
CO2: light on - 35ppm, 40ppm just before light out
KNO3: once every 2 days, adding the equivalent of 5ppm
KH2PO4: dosed with KNO3, adding equivalent of .5ppm
LGA: alternate with Kno3 dosing, 20 drops.
I don't dose Ca or Mg. But I do have some coral chips buried in the gravel that gives me 5dgH.
Maybe Mg can come from weekly water change? I'll try dosing MgSO4 this evening. (Has anyone tried magnesium carbonate from climber's chalk?)

Is it worth the trouble to rebuild the base fert? Or should I continue with just dosing liquid fert. If its the latter, what am I missing to cause the bigger plant such grief?

Thanks for your replies.