Botanicals vs. Peat- the discussion continues...

One of the questions we receive a lot about botanicals is just how effective they are at reducing the pH of your water. Now, I know we've had the discussion earlier in the week regarding the influence of Catappa, and how your source water's pH and hardness will affect their effectiveness at reducing it.

A lot of you want to know how botanicals do at lowering the pH of your water versus, for example, peat moss.

It's a good question about the botanicals. Many of them do impart some similar effects as peat, with materials like Catappa leaves, Catappa bark, Cutch Tree Bark, Coco Curls, etc. being most similar in how they do this. You know, putting tannins and humic substances into the water...that stuff! I'd say that most of the pods will add some visible tint to the water, but their pH-reducing effect is far more limited.

As we've discussed repeatedly, the starting pH and hardness of your source water is probably the biggest single factor influencing how much any botanical materials will be able to reduce it. And of course, exactly how much humic substances, humic acids, tannins, and other compounds that can do the job varies from botanical to botanical. I have heard one capability attributed to peat- and that is it's alleged ability to function as an "ion exchange" media, sort of like what happens in an RO/DI unit. I can honestly state that I don't know if this is true or even possible, but it has very, very interesting implications if it is!

Now, to be perfectly honest, I don't know if any serious, scientific study has ever been done on how much of these substances leaves, pods and other botanicals can actually impart to the water...and I'm not even 100% certain if such a study has been done specifically on peat moss, either! It would be pretty cool. Perhaps it has been done on peat, because it's been used in aquariums for many decades...I may have to dig further to see if there is such as study!

In years past, I played around with peat in aquariums quite a bit for various applications, and I'm a big fan of it...conditionally. That is, much of it has been harvested from nature in a non-sustainable way, and that makes it kind of unpopular to use! It's why I haven't offered it on our site, quite frankly. 

Now, there are some North American suppliers of peat in Canada and the US which have developed sustainable harvesting techniques for peat, and it certainly would feel better using there stuff. I've held back from offering it on the site simply because I don't want to have to "defend" the use of peat (even if its from a certified sustainable source) to the casual site visitor who may not read the "Hey, this is sustainably sourced!" stuff! However, more and more hobbyists are asking, so it's something we may eventually offer at some point.

And of course, there's that decorative aspect. I mean, peat looks cool, right? But botanicals- well, they add a totally different aesthetic touch! And that's the cool have lots of options and choices. And, with proper water preparation, the impacts of all types botanicals can be "managed."

Where am I going with this? Short answer- I like the effects of peat in the aquarium. I even like the looks of it. If you can obtain it from a good source which uses sustainable practices, and the product is free from additives or fertilizers- I'd utilize as desired. It really can affect the pH of water better than most botanical items can (of course, to what extent depends upon your starting dKH and pH.)

We do have an interesting sort of alternative in the form of Cutch Tree bark", which looks and performs an awful lot like the long-fiber peat moss I grew up playing with in my killie tanks "back in the day."

And our coconut-coir based "Substrate Fino" is a super-fine variant that could also be a substitute for peat...

And catappa bark fills a similar role, although it's equally adept as am aesthetic/hardscape component.

That being said, as they say- there's no substitute for the real thing, right? I have not been in the habit (maybe I should be!) of asking you-our community- if  we should or shouldn't do stuff; however, this is a rather polarizing and important topic, so I want you involved!

Do you want us to offer peat moss as a botanical product, if it's from a sustainable source?

Let us know here, or on Facebook.

Stay involved. Stay practical. Stay open-minded. Stay curious...

And Stay Wet.


Scott Fellman

Tannin Aquatics  



Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

October 24, 2017

Here in Southern California, we have what we jokingly call “liquid rock”- the water is so hard. Our method is to use RO/DO units to soften the water (can’t trust Los Angels’ smog-infused rainwater unless it’s been raining for several consecutive days to sort of “cleanse” the atmosphere- and those are rare events! So, yeah- use what you’ve got- and I LOVE that you’re able to do that! And the no filter thing freaks a lot of people out…it shouldn’t- just because something seems contrary to usual practice doesn’t make it “wrong”- right? :)


October 23, 2017

I fought against my high-nitrate rock-hard tap water for a few years. Peat had no appreciable impact on the hardness. Today I use a mixture of tap water and rainwater, because soft water literally falls from the sky.

I did develop a reliable method of running my tanks with zero nitrate, but people don’t seem to like it when I tell them I don’t use filters…

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