Keeping Tannins in tank

[DayTripper1]

I have a question.
I have set up a 15 gal fluval flex 2 tank. I used fresh driftwood that do leach tannins. I use seachem matrix and sponges for filtration only. No carbon or any other material in filter. I use aquasolium as a substrate with java ferns and Anubias planted in the tank. When I put the driftwood, alder cones, Catappa leaves, and blackwater extract in the tank it turns amber for a little while. I have also slowed the flow of water thru the filters. Overnight the tannins disappear and the tank is crystal clear in the morning I have asked Seachem about this and none of their products used will remove tannins.
PH is 6.1 Low KH 2-3 according to the api test kit
The tank is finishing up its cycle. Ammonia is at 0. Nitrites are coming down. I am at a loss here on what is causing the tannins to dissipate.
Any clues?

 

[Tomsfish8 7]

I can't answer why your tannins are vanishing but driftwood stops expelling them eventually.
Some of the effects from alder cones and catappa leaves are not always visible.
Light can degrade just about everything we add to tanks IME.
When I wanted visible black water I added a humic acid for hydroponics.

A little goes a long way.

 

[DayTripper1]

I can't answer why your tannins are vanishing but driftwood stops expelling them eventually.
Some of the effects from alder cones and catappa leaves are not always visible.
Light can degrade just about everything we add to tanks IME.
When I wanted visible black water I added a humic acid for hydroponics.

View attachment 387639
A little goes a long way.

I can try that, but I do add a blackwater extract from Brightwell Aquatics and the aquasolium substrate is supposed to be humic. If I take the driftwood out and put in a bucket of remineralized RO water it turns dark amber. Put it back in the tank and nothing. Very low lighting. Mostly red and very little white and blue spectrums.
It is possible that once the cycle is complete, tannins will stick around.? I dont know. I have never had this problem