[bartoli]

When I re-do a soil-based tank, I always throw away the existing soil that was in the tank. Having read the discussion 'How-To: Mineralized Soil Substrate, by Aaron Talbot' I was wondering can the soil in an existing tank be re-cycled by air-drying it and then sealed in a bag for re-use in a later day in another tank?

I know soil is dirt cheap in monetary term. But I try to reduce the amount of garbage generated.

Thanks.

 

[bartoli]

Hi Stepheus and Aaron, thank you for your reply.

Regarding soil mineralization, I did think of trying it when I first read the thread a while ago. However, my understanding was that it was mainly for preventing algae. But algae was not an issue for me (probably due to the low light setup combined with plenty of floating plants).

I guess what really stopped me from trying it was that I did not fully understand how the mineralization process would affect the soil's life span. For example, I remember reading in Ms. Walstad's writing that adding CO2 will use up the soil's nutrient at a rate much faster than it is being replenished through feeding the fish (if I have mis-understood her writing, please correct me).

May be I should ask: When people maintain their tanks using Ms. Walstad's way, will the mineralization process affect the soil's life span?

Thanks.

 

[bartoli]

Thanks Aaron. I have two questions in mind.

When the soil is not mineralized, will the same nutrient be available at a later time?

Does the mineralization speed up the release of nutrients that would otherwise be available at a much slower pace?

Thanks.

 

[bartoli]

Aaron, if I understand your explanation correctly, preparing the soil through mineralization will thoroughly expose the soil to oxygen. That will result in a massive release of nutrient within a relatively short period of time. Without the mineralization preparation, much of the soil nutrients remain trapped due to the lack of oxygen. Later when plant roots release oxygen, those trapped nutrients will then be released, albeit at a much slower pace than through the mineralization preparation

However, given the limited amount of nutrients in a fixed volume of soil, the mineralization preparation will cause the soil nutrient to run out much sooner than otherwise, unless we replenish the nutrients through massive dosing. Have I missed or mis-understood something?

Thanks.

 

[bartoli]

Sorry Aaron, your first explanation came across ok. Just that I was not expressing myself well. Let me try again. Hope this time will be better.

Nutrient release is a multi-step process. One of the steps depends on the availability of oxygen. Mineralization preparation speeds up (or even completed) that oxygen-dependent step by making sure that soil has been exposed to plenty of oxygen before being used in a tank.

Soil that has not been through the mineralization preparation will be constrained by the limited amount of oxygen generated by plant roots. Thus, the amount of initial nutrient release and the continued rate of nutrient release will be much less than those of the soil that had been through the mineralization preparation.

Mineralized soil does not have oxygen constraint. It can therefore release a massive amount of nutrient in a newly set-up tank and its continued rate of nutrient release high.

But for a given quantity of nutrient, the more rapid it is being released, the sooner the nutrient will be completely depleted.

One way of replenishing nutrient is through fish food. But if the soil nutrient release is at a much faster rate than that of the replenishment from fish food, soil nutrient will run out. And that is my concern with the impact of mineralization preparation.

 

[bartoli]

It takes 3-4 weeks for the bacteria to establish in the substrate that help the plant's roots to unlock the nutrients from the soil.

Soil comes with plenty of bacteria. Does the mineralization preparation process kill those bacteria and therefore we have to give 3-4 weeks for the bacteria to grow back?

The nutrients are never released anywhere, rather they are unlocked and use by the plant's roots as needed.

What is stopping the nutrients from being released into the water column?

Thanks.