Active substrate pH buffering for caridina shrimp

[BenAquatics]

Active substrates (a.k.a. aquasoils) are often recommended to reduce pH and keep pH stable for caridina shrimp. However, active substrates are expensive, require replacement once depleted, and are difficult to replace with new active substrates because new active substrate tends to leech ammonia.

What is the ingredient in aquasoils that provides the buffering effect? A Google search (not sure if I'm allowed to post links here) says that aquasoils are baked soils with peat added for buffering capacity. If that's true, can I use peat moss instead of aquasoil in caridina aquariums?

[Fish Folk]

Interesting question here. I’ll share a perspective, and hopefully others with more specific experience can help you out as well.

Is your main concern: (1) the health, longevity, and propagation of Caridinas?  or, (2) the flourishing of a heavily planted aquarium?

If you’re just trying to naturally lower pH, adding Catappa leaves and alder cones may help.

But if your concern is about buffer and good minerals to promote healthy exoskeletal growth, you’ll need to consider other factors.

We use crushed coral with our Neocaridina shrimp in soft water. I do not ever try to chase pH. I just watch the shrimp. If they’re healthy, I’m fine.

I am not sure that the soil actually loses anything relative to the livestock over time. Mulm will revitalize soil over time, in my opinion.

Peat moss is definitely a pH lowering substance, but I think _not_ a buffering agent.

A buffer like crushed coral or wonder shells adds hardness which stabilizes pH swings in soft water.

Do you know your aquarium’s current pH? GH? KH? 

Edited December 22, 2021 by Fish Folk

[Mmiller2001]

From my understanding, the high CEC value of aquasoil pulls carbonates from the water which causes a reduction in pH. When bacteria in the soil begin doing bacteria things, this process lowers the pH in the soil and ultimately contributes to the water pH as well.

[BenAquatics]

I don't keep caridina yet but here's what I've read online:

• Certain caridina species, including crystal red shrimp (CRS), prefer acidic pH and very low kH. Some caridina species don't need low pH (e.g. tiger shrimp), and some caridina species that originate from low pH environments can adapt to non-ideal parameters, but for the purposes of this question let's assume it's a high-grade CRS that's inbred and intolerant of less-than-ideal parameters: acidic pH and low kH.
• To provide optimal conditions, caridina keepers will use RO water and add mineralizer to increase GH. RO water has a neutral pH, so we need to add aquasoil to reduce the pH.
• Since caridina prefer low kH, the aquarium is subject to pH swings. This is why we need some active substrate to keep the pH at ideal levels.

The TLDR of what I've read online is that active substrate reduces the pH to a certain level (6.0-ish) and, more importantly, it keeps the pH stable at that level even when the aquarium has low kH.

What I haven't been able to identify is this: what's the magic sauce in active substrate that provides this alleged buffering capacity? Can this be reproduced without using expensive aquasoil?