Safe T Sorb #7941

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Aug 16, 2023
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Florida, USA
There are many posts online, including from Diana Walstad, herself, about the use of Safe T Sorb and similar products as components of a planted tank substrate. One obstacle with the use of these substrates is that the ability of them to attract and bind minerals from the water can be dangerous to people with already soft or RO water. This requires one to “charge” the product with minerals until it is at or close to capacity.
There are suggestions and recipes online, but all of them are educated approaches and not soundly tested science.

Since I will be using this as part of my 75 gallon planted aquarium substrate, I thought I’d share my reasoning and approach, and why I’m using it.

I mainly wanted to use the product because I dislike the little round balls of most modern planted substrates. I also didn’t want to pay a premium price for the limited benefits of Seachem Flourite, though this was my original plan. The lack of nutrients and CEC in Flourite made me feel there was better options.
With a higher CEC, the substrate can bind and hold buffering minerals and plant supporting nutrients, essentially creating a partially self fertilizing substrate, where fish are well stocked and well fed.
This is the primary benefit over Flourite and neither option provides much on their own in terms of plant nutrition.

The idea of “charging” the substrate first intimidated me at first. I had to read again, about the various interactions and components of kH, GH, and pH.
Additionally, I was unsure if I wanted to charge the substrate with nutrients, in addition to minerals, to boost plant growth.

My intention is to use this Safe T Sorb over a laterite layer, mixed with and covering a dirt layer, then capped with sand. I also plan to add some Osmocote to the dirted layer.
This article explains how the substrate will only bind certain forms of ammonia:
Because of this, and also because of Diana’s experiences with Safe T Sorb, I don’t see any reason to attempt to permeate the media with nutrients. The potting soil will have access nutrients and I can always dose the water column. With the substrate being properly charged with GH and kH, it shouldn’t pull all of the nutrients out of soil, anyway.

In order to charge my media, I’ll be using Seachem Equilibrium ( GH ) and Lake Victoria buffer ( kH ). This will charge the media with Calcium, Magnesium, and Potassium to maintain a uniform buffer. I’ll be mixing enough for 9 dh and 7.4 pH, with the kH buffer for a 5 gallon bucket of media and I’ll be allowing this to sit and adding additional buffers until it no longer drops the GH or pH after a week of sitting. I’ll be buffering my tank water to 6dh and 6.5 pH, and doing a dark start. This will give me an opportunity to adjust the GH and pH over the course of the dark start. The dark start will be more
prolonged the more adjustment that needs made, but I’m confident that I’ll develop a feel for how much buffer to add to the media in the bucket stage, base on how much and how quickly it drops the values, so that by the time all is assembled in the aquarium, minimum adjustment will need to be made.

I’ve simplified this greatly and avoided too much over my level of understanding explanation of the complex interaction between the 2 buffers and pH, but Calcium, Sodium, Potassium, and Magnesium are all important on the cellular level and interact to create stability in the water and in all of life.

I to have a successful setup and be able to share the progress as I go and I hope the information proves useful to the forum.

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