[planty]

Hey everyone,
I have put some natural cork bark into my high tech aquarium (after cutting and shaping it until it looked just right ), only to discover that after almost 2 months it seems to be "melting" away... (shrinking in size, shape change etc)

Does anyone have any idea why this is happening?
Could it be my Excel? dry ferts? co2??? that is causing this problem?

I used it under the assumption that it would last for a very long time...

In the meantime I have stopped using Excel. Hope some one can shed some light on the subject for me.

Thanks,
Planty.

 

[lochaber]

Do you have any pics (a before and after would be preferable, but even just a current pic may help).

Also, I'm assuming it's virgin cork bark (the type that looks like bark, and is sold in tubes and curved sections) and not the type they use for bulletin boards/flooring?

 

[planty]

I do not have a good before pic. But here are a few as of today ( iphone pics..)
There is a crack from the bottom right to the center that was not there before. Plus the distance to the glass is much greater than it was. There are more little changes that are harder to point out...

Hope u can make sense of it.
Thank you.

 

[lochaber]

My best guess is that despite cork being very water resistant, it is absorbing some water and warping, causing it to bend and arch away from the glass.

Not sure about the melting/decay bit.

I've used cork bark in palludariums before, but not in aquariums. I read one account where someone used it to terrace the substrate (may have been on here, I can't remember) and it seemed to work pretty well, but after a few months the pieces detached and floated up.

 

[Diana]

I have used a different species of oak bark (cork is a species of oak) and it does change shape when it is under water. I do not know why, except in one case: Loricariads will eat it. My Royal Pleco scraped one piece down from 2"+ to about 1/4" thick. Took a few years!
Other pieces have split, curled or flattened out as they absorb water. Then they seem to stay almost the same, but not quite. Perhaps it is decomposing. This takes a while, but if you have used it in a place that required a near-perfect fit, then I suppose you would see the difference a lot sooner.

 

[planty]

Thanks lochaber and Diana for your replies.
The more I think of it (and look at it), I can assume you are right and the bark is warping. What was a little nick now looks like a big crack, and its getting larger :-(, I've noticed in the last few days a bigger change in the overall shape.

Hope the worst is behind and that it will start settling soon.