Can a lot of tannins and a low KH from tapwater lead to BBA?

[jhays79]

My well water is on average a GH of 150ppm and a KH of 50ppm. I set up a new tank with a huge piece of driftwood that is leeching tannins very heavily. Am I correct to believe the tannins in the wood drive down the ph? How does my already low kh tie into this? I'm thoroughly confused!

[Jeffww]

Acids will reduce carbonate in the water. Nothing to do with bba.

[Zorfox]

Originally Posted by jhays79

My well water is on average a GH of 150ppm and a KH of 50ppm. I set up a new tank with a huge piece of driftwood that is leeching tannins very heavily. Am I correct to believe the tannins in the wood drive down the ph? How does my already low kh tie into this? I'm thoroughly confused!

Tannins will reduce PH. However, your "Low" kh is actually high. Most prefer KH around 4-5. Most plants seem to tolerate KH from 2-20ppm. I would assume the tannins will be buffered by the carbonates. HOWEVER...

Originally Posted by Wikipedia

"The term "tannin" by extension is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other suitable groups (such as carboxyls) to form strong complexes with proteins and other macromolecules."

How those compounds are incorporated into the acid base balance system I don't know.


Below is an interesting fact I didn't know...

Originally Posted by Wikipedia

"Tannins are incompatible with alkali's, gelatin, heavy metals, iron, limewater, metallic salts, strong oxidizing agents and zinc sulfate, since they form complexes and precipitate in aqueous solution."

"The tannin compounds are widely distributed in many species of plants, where they play a role in protection from predation, and perhaps also as pesticides, and in plant growth regulation."

[Jeffww]

Originally Posted by Zorfox

Tannins will reduce PH. However, your "Low" kh is actually high. Most prefer KH around 4-5. Most plants seem to tolerate KH from 2-20ppm. I would assume the tannins will be buffered by the carbonates. HOWEVER...




How those compounds are incorporated into the acid base balance system I don't know.


Below is an interesting fact I didn't know...

KH 4-5 is actually 80-100ppm carbonate. The german scale is ~18ppm = 1 degree.

His KH is perfect. Most plants enjoy anywhere from 0-5,6, even 7 kH. However pickier plants will often prefer 0-2KH.

I also didn't know that tannins complex with metal salts. It might be something to look into when fertilizing.

[Zorfox]

Originally Posted by Jeffww

KH 4-5 is actually 80-100ppm carbonate. The german scale is ~18ppm = 1 degree.

His KH is perfect. Most plants enjoy anywhere from 0-5,6, even 7 kH. However pickier plants will often prefer 0-2KH.

I also didn't know that tannins complex with metal salts. It might be something to look into when fertilizing.

You're absolutely correct. I misread the 50 as degrees not ppm (which was clearly stated). Sorry for the misunderstanding.

Yes, that snippet from Wikipedia was news to me. Interesting and does warrant investigation for tanks with high levels of tannins.

[jhays79]

So should I be worried about the ph dropping from he tannins? Or should I just do water changes to reduce the acidity of the tannins? I'm thinking ph swings are bad

[Jeffww]

pH will go down but only slightly. I wouldn't worry. But it may be unsightly to you.

[Zorfox]

Originally Posted by jhays79

So should I be worried about the ph dropping from he tannins? Or should I just do water changes to reduce the acidity of the tannins? I'm thinking ph swings are bad

Sorry that was my mistake. I misread your measurments. The swings should not be significant with the KH levels you have.

[jhays79]

Thanks for all the help guys!