oak leaves

[sasikan]

how long do you keep the oak leaves in your aquariums? after one month or 2 they start to disintegrate, do you leave them in there and just add new ones ,or do you vacume them out? don't they rot after a wile and pollute the water?

 

[tjudy]

I leave them in and remove the small particles with regular water changes. Eventually I pull out the skeletons.

 

[dw1305]

Hi all,

don't they rot after a wile and pollute the water?

They do, but this decomposition has a very limited effect on water quality, because the leaves have already lost their sugars and proteins, and all that are left are the structural carbohydrates and complex carbon compounds (tannins etc) that are inhibitory to microbial degradation. Scientists use something called BOD, (Biochemical Oxygen Demand), to quantify a substances polluting ability, and these leaves have a low BOD.

Even a tank full of dead oak leaves is going to have less effect on water quality than a small amount of proteins or sugars. These will cause a bacterial bloom and this will rapidly deplete the oxygen from the water. If you want to compare their effect you could try equal weights of grass cuttings and dead Oak leaves. The BOD of the grass cuttings would be at least 100x that of the dead leaves.

This is from an interesting study available from: <http://consensus.fsu.edu/fertilizer-task-force/industry/Decomp_Study.pdf>.

The samples then stabilized at weights between 13 and 20 grams for the duration of the 180-day sampling period. No attempt was made to differentiate between percent decomposition of grass to oak leaf ratios, but observations made on the mixture throughout the study revealed almost total solution of the grass, with little obvious physical decomposition evident of the oak leaves, even out to the 180 day mark.

Have a look here for some tannin/decomposition details about differing leaves: <http://www.pitt.edu/~mbtraw/2010%20Traw%20&%20Gift%20ABT.pdf>.

cheers Darrel

 

[sasikan]

glad to know that its not as bad as it seems (whenever i add new water all these tiny pieses of oak leaves scatter in every corner of the tank ) the fish seem to be ok but i just wanted to be sure i was not polluting the water thanks!!

 

[hengyi86]

Very informative! thumbs up for you!