I'm trying to make use of soil for my tank's substrate. but what soil? since i read Diana Walstad's books i have researched more and more to answer this question. but it was vain!
I am going to try a %100 full peat soil that contains :
Coconut Fiber,AcidicPH,Perlite,Coal dust,Clay,Leca,Nutrients Micro&Macro Elemts,Low EC,the lowest level of salt in the soil.
well as we know the ideal PH for plant growth in substrate is 6.6.if the PH is too high,metal oxides form and nutrients like iron become less available to plants substrate. coconut fiber very slowly decrease PH,in the front of it common peat does this action so fast and it leads to metal toxicity to plants.
i want to submerge this soil for almost a month to let bacteria provide ready nutrients for plants.
my first question is : do you approve the soil?
after preparing mentioned soil i am trying use this substrate (its the picture of my tank
it has 1-2 mm diameter and so heavy! i tested it in vingear and slowly some bubbles came out. so should be alkaine substrate. in walstad bible(!) Vallisneria spiralis grew just as well in an alkaline desert soil(ph=8) as topsoil from his yard! well it so complicated for me!
in theory i can mention this advantages of putting alkaline substrate on top :
1-it oxides metals and nutrients from above water. so many nutrients will be out of reach of algae (who is so happy to see soil in substrate!) and flow this metal oxides into soil,therefore plant will readily take it up!
2-it has calcium which is vital for plants(many soil-based planted aquarium add calcium carbonate or bone to soil)
now,whats your opinion?
thank you in advance