Will leave it to the boffins to get into particulars of PPS pro
@M.eremin but in a nutshell, to ensure availability of all nutrients to your plants from multiple locations.
If so, why do we need soil?
Folks play with different methods of nutrient delivery.
@Ady34 did a cracking 1500 tank without soil. Worth checking that journal out if you’re interested in inert/no substrate instead of soil based done proficiently.
Alternatively, if you’re also going high light/co2 injected, rich substrate and the minimum input into the water column (potassium and micronutrients) for the first few months of a planted tanks life is one method. You’re splitting the locations of nutrient delivery with nutrients ending up in the plants as fast as possible, rather than having high nutrient availability in the water column during a time when a tank may be more prone to algae.
Equally EI (Estimative Index) dosing with rich soil works very well too if fast growth is your game. Unfettered water column nutrient availability with the backup of an active substrate.
If I use soil, do I need to maintain the same water parameters?
As you can see above, there is no single answer to this question. What you’re dosing, how much you’re dosing and what outcome you’re trying to deliver are entangled with this question.
How heavily planted is one variable. Another is how good your plant husbandry is. There’s a certain obsession with consistency with dosing rather than keeping an eye on what your plants are telling you.
You cut plants, you’ve changed the overall plant mass, you’ve stimulated new growth, you’ve changed demand. Consistently healthy plant growth is the outcome, what you input is just the vehicle to get you there.
