I keep alot of "softwater/blackwater" species. I will add my input based on about 7 years of experience but no real scientific data that I can cite. Most of it is anecdotal but all based on experience.
I use leaf litter (almond and oak) as well as driftwood and alder cones in all my sa tanks. I also use them frequently in my asian and indian tanks for the invertebrates. I have not noticed any detrimental effects, only benefits. Personally I like the effect, the fish are more vibrant, my fry grow quicker, and I have a higher yield.
1. Creating natural conditions for comfort/lower stress.
Alot of the fish I keep, especially smaller tetras from blackwater conditions are pretty much prey. Their colors are often vibrant for them to show up to each other to school in these dark conditions. They are often safer in the leaf litter/branches than they would be in clearer open water. It seems intuitive that providing these conditions would lessen their stress, especially if one has a "centerpiece" fish designed to stress them into schooling.
2. Promoting breeding behavior
Some species which we breed readily in tanks in caves are more typically in the wild leaf litter spawners, apistogrammas are a great example.
3. Increased brood/survival rates of fry
-It is said that various chemicals will aid in preventing fungus growth on eggs
Using leaf litter or driftwood produces infusoria or paramecium, which new fry will readily eat. I also use both in all my dwarf shrimp tanks as its an easy way to feed them wihtout overfeeding and having the resulting planaria. Filter squeezings are another alternative.
4. Medicinal usage
- Treatment of some ailments such as bacterial infections, fungal infections and the whirling disorder found in characin species
I use alder cones to prevent fungus, if replaced every few days, I have much less fungus of eggs than I did previous to using them wiht no other change in conditions. Again, because I keep so many invertebrates, I am leery of using chemicals in most of my tanks.
I am also curious as to what exactly we are getting from the blackwater extract. I couldn't find an ingredients list for the Tetra brand extract, so if anyone has a bottle handy, please feel free to post it.
I have heard talk of using specific acids to spur the same results as they are a part of the total extract, if I am to understand it correctly.
A few of these chemicals have shown up:
-Tannic Acid
-Humic Acid
-Fulvic Acid
Depending on the actual chemical makeup of the extracts vs what is necessary, you could easily make your own extra formula to use in your home aquaria.
Thoughts, comments and contributions?
I use leaf litter (almond and oak) as well as driftwood and alder cones in all my sa tanks. I also use them frequently in my asian and indian tanks for the invertebrates. I have not noticed any detrimental effects, only benefits. Personally I like the effect, the fish are more vibrant, my fry grow quicker, and I have a higher yield.