Are tannins beneficial to axies?

I was reading up on tea baths, and I read that the proper tea to be used for tea baths is black tea because of the higher tannin content. The tannins help block bacteria growth, which seems pretty awesome. I have a few pieces of Malaysian driftwood in my tank that leak a good deal of tannins into the water. I have read that they are harmless, except for the tan color it gives to the water. I have heard some people trying to remove the tannins, but I was wondering if they are actually helping my axies out by preventing bacteria growth. Anyone know anything about this subject?

Hi Shizeric,

As a matter of fact tannins can be very benefitial. Here we add the leaves and/or bark of the tropical almond tree to our tanks specifically for maintaining a level of tannins in the water. Other options are the leaves of beech or oak trees (collect dry leaves in fall and store them in sacks for the rest of the year; pour boiling water over them to sterilize them before adding to tank). Many people I know keep these leaves in their tank all the time as a preventative measure, although then there is the question of whether a tea (or other leaf) bath will help should an outbreak of fungus, etc., occur. Everyone I know here uses the leaves when cycling a tank with animals.

Hope this helps - if you have questions, fire away!

-Eva

Presence of tannins can help inhibit certain pathologens from establishing in the tank, particularly those susceptible to tannic acid. The common saphrophytic (and opportunistic) saprolegnia doesn't do so well in water with tannins.

Although tannins have an astringent effect in animals with pores (hair follicular structures), their efficacy in axies is less so, simply because axie's don't have pores in their skin in the same way mammals do. Rather axies have a slime coat layer that has plenty of defense antibodies (secretory IgA) and circulating white cells to help fend off pathogens under their skin. Tannins do however prevent some types of bacteria and fungus from attaching to the axie skin (interfere with attachment pili) and hence preventing them from colonising.

The downside to having tannins in the water other than aesthetic reasons (brown water), is that they can cause water pH to fall. As a result, other water parameters may be affected as well and you would have to monitor the parameters and perform water changes diligently. The types and proportion of beneficial bacteria in the tank can also be affected. What can deter pathogens also deter helpful bacteria. This is a minor problem provided you are regular and consistent with tank management.

Thanks to both of you.