Does Tannin Affect Fish ?

[moochy13]

i brought 3 new bits of bogwood and they have ben soaking for a couple of weeks or so and although the water gets a bit clearer every time i change it, its still too brown to be considered as fully leeched. im about to start cycling my tank (fish in or out not sure yet) but either way im going to be doing big water changes, so if the wood keeps leeching i will be on top of it.

if i decide to cycle fish in, will the tannin affect fish or bacteria ? im assuming not due it being how it is in the wild, but thought id better check.

 

[KittyKat]

A for fishless from me!

Tannins effect soft water fish normally in a positive way.

 

[elisew]

+1 for Fishless cycle

Anyway, no the tannins wouldn`t hurt the fish, it`s just unsightly for some people to see the water a dirty colour instead of being nice and clear. You could put some activated carbon in your filter which would help to remove the tannins, that and regular water changes would be the best way of keeping your water clearer.

 

[the biffster]

1 up for the fish less cycle
if you are going to do a fish less
cycle stick the bog wood in a bucket
and soak while your doing your cycle
that way it wont be leaching any tannins
by the time you need to use it in your tank

 

[JoshuaA]

I found the best option was to cycle my tank with the bogwood in it! The reason I think it worked wonders for me was the fact that the bogwood leeches faster at higher temperatures, I found that it was awkward and mostly impractical to heat it up in water every day and leave it in a bucket for the rest of the day so I looked around me for the closest thing to a large quantity of warm water... I saw my tank.

The Tannins did not stain anything in my tank and my cycle took a few weeks doing a water change each time the water failed to pass an acceptable level of clarity due to the tannins. By the end of the cycle I would say my bogwood was leeching tanins at the same rate you would expect from any other tank with old bogwood in.

The bogwood brought the pH down slowly but I was also using Bi-Carb to force the pH up to encourage bacterial growth.

I followed that 29-30 degrees and a pH of ~8 was the best conditions for bacterial growth. The tannin did not seem to effect the process at all in my cycle/s.

 

[waterdrop]

Agree with JoshuaA that its fine to kill two birds with one stone (gee, is that a bad saying on a site like this ) and that the tannins are just fine for the fish (the amazonian fish love tannins) and that countering the downward effect of the bogwood on pH with the upward effect of bicarb is just fine too. WD