Hi all,
@Gulczi, there are a few things to consider when trimming.
As the plant grows, it changes its "machinery" to adapt to current conditions (in the same way we get into a routine). If the conditions in your tank vary*, then then leaves on the bottom may be configured differently than the ones on top.
*every moment when growth occurs, when detritus develops, when obstructions happen, flow patterns are "changed". Now, the impact from 1 second to the next is extremely small so it is not worth out time considering. But if you allow the growth to occur over a month or two and then do a massive trim, the leaves which were originally engineered to these circumstances have now been shaded/have a different environment ... and they may have adapted again ... or died (due to lack of nutrient delivery).
So, when we trim, we consider the "machinery". If you have a tall tank, then the impact of trimming down the stem is larger than doing a 1/3 trim.
Now, if you provide ideal conditions for plant growth and have a healthy plant that you are trimming, it really doesn't matter - it will used its stored energy (in whatever you have left) and create leaves and stems which are adapted to the "new" conditions. (We ALWAYS want to have healthy strong growing plants in the tank for stability - if we put our plants in a situation that is unfavorable ... they will make it .. probably ... but the system will be "stressed" ... which is fine - as long as we are aware and can respond appropriately).
The top that you replant has a bunch of stored energy (since it was healthy), so it will throw roots and begin growing.
You can either:
1) trim it a little bit and replant the tip elsewhere
2) trim it to the ground and replant the tip elsewhere
3) you could pick the tallest stems and trim them:
@Mick.Dk mentions the "Black Current Method" <
here > which I will be personally trying soon.
In every case, you need to ensure that your conditions are ideal for plant growth (nutrients, co2, flow/distribution, lights, temperature).
Dennis Wong has a great video here:
The best part is this:
Even if it isn't bushy by the "end" of this attempt, you can just uproot/top all of the new growth that you have and start again!!!!!
This time though with more stems to play with.
Josh