Still I have to wonder how "lean" the water column actually is. Seems like there'd have to be a lot of nutrients leeching into it?
Which doesnt change the fact that plants seem to love having tons at the roots, just wondering if we can actually call it a lean water column...
Good point Joe. I am really surprised it is working so well with so much light. It’s got to have some stuff leaching in the column... Vin, your thoughts?
I am certain there is SOME leaching going on. But since I don't disturb the substrate much or uproot stems, the leaching is probably minimal.
Two reasons why I think leaching is minimal:
- Little to no algae given the amount of light.
- The Water Lettuce that were 8" diameter a few weeks ago are now 2 to 3" diameter at the most. So the water column is nutrient limited. That's the beauty of having floating plants - they are not light or CO2 limited. Floating plants are really good indicators.
Makes sense the second reason Vin, but the first one is not clear to me... it is right because you have high light that your plants would need more ferts from the water column than without. Isn’t the rule “the more light, the more ferts must be given”?
Reason #1 was...if there is ammonia leaching into the water column, I would not be able to go this long without needing any glass cleaning. I do water changes every 15 days now and still, no need to clean glass. If there was uncontrolled leaching into the water column from the 1 lb of Oscmocote, I would imagine there would be some imbalance of some sort. So, at the very least I'd expect some GDA from the N being leached into the water.
Unbalanced tank + high N in the water = GDA
Unbalanced tank + no N in the water = no GDA (but other kinds of algae)
As for high light, yes, nutrient demand will be higher. But there is an excess of nutrient in the substrate. Water column can be completely devoid and plants will still be fine.
That Tulu looks great. I got rid of mine since it only stayed green and some white on top and looked uninteresting, but now, looking at your pic at think I didn’t do it justice.
Fantastic update Vin! It's amazing how well Cuphea is growing with just root feeding, in my small 20gl farm tank with EI and high Co2 doesn't grow at all. I'll try to feed it through the roots with some osmocote and see if it makes any difference, as you suggested. I am curious to know if Joe (Burr) can grow that plant in his tank with just water column dosing.
Also, one question: do you use nose-bleeding Co2 in this tank as well?
what is your parameters at this point?
Im noticing that low Fe helps in my tank. Increased, leaves stunted, then i decreased even more than it was .2 fe to .1. plants are thriving now.
I got rid of mine
I hope you gave it to someone else instead of chucking it.
FWIW I maintain .4ppm of Fe in the water column @ all times, not sure what is delivered from the capped soil.We haven't figure out the rapid-on and rapid-off white leaves at the top are really iron-related.
Burr generally side-steps Lythraceae other than the Mac green, Mac Variegated and wallichii to some degree. I don't remember if I've shipped him Cuphea anagalloidea. May have. I'll have to send him some.