Wood for tanks??

Dunno if this is the right section to put this under, but there has regularly been a question I've pondered regarding which woods are suitable for the aquarium?? I know that Mopani wood or bogwood is fine, but what about tree branches?? I have numerous trees that I've cut down, and wondered if its possible to use them in the aquarium?

Since I haven't really heard of branches being used, I assume that there is some reason for this that prevents their use?? Are they poisonous? Do they alter the water chemistry? Obviously this would all be dependant on the type of tree?

Cheers
Big G!

 

I would be reluctant to use any wood unless I know that it contains no toxins. There are, for example, certain woods that you cannot make a fire with for a braai. I wouldn't use those in a tank either.Furthermore, you need to ensure the wood is thoroughly dried out and not rotting before you start curing it. The curing process involves sterilizing it in boiling water for a couple of hours, followed by submerging it under water for about 2 months. This will allow most of the tannins to leach out. You will notice the water turns yellow/brown while curing the wood. Keep changing the water until it is pretty clear. Some wood leaches little; others more. Soft wood (e.g. pine) is also dangerous, because it decomposes faster than hard wood (e.g. mopani). That being said, there may be some soft pieces on hard wood. Remove these. So best inspect the wood before using it. Remember: even wood you buy from gardening centres or pet stores need to be cured before use.

 

Yer, I thought it would be that we can't use most woods, but just thought I'd check!

I have Mopani wood in my tank, and even after leaving it for several days and into weeks to soak the tannins out, they still turn the milk chocolatety! They are now in my tank and still the water keeps on darkening over about a week or so between changes! Its been three months now and its still leaching!

Is it possible to remove these tannins thru filtration system?

Sorry if this all seems so basic, but all the books I have are very unclear!

Cheers
Big G

 

You can use carbon the the filter to remove the tannins. The amount of carbon depends on the amount of tannins. You will have to experiment. But I read a few posts where people said this didn't work. However, it works for probably 90%. Also, carbon needs to be REPLACED every 30 days.

Remember that when you medicate, you need to remove the carbon, as it will absorb the medicine too.

 

Bottle brush and other Protea family are safe.

 

I also know willow and guava to be safe as well - must be bone-dry and cured though

 

Is"nt there a way to reactivate carbon?

 

no. it leeches back into the water if you dont remove it.

 

Now i remember, i knew i had it some where in my head.
You can reactivate it by taking it out and throughing it in a strong saltwater mix and it wil release what ever it took out of you tank. You can only do this once and then through the carbon away.

 

This is only a myth. "The pollutants are chemically bonded to the carbon and for them to be released it takes acids, steam or extreme heat...like 1500*F...not many things that are available in an aquarium or a pond."

http://www.koiphen.com/forums/showthread.php?t=43455&page=1&pp=10
http://www.eastcoastaquariumsociety.ca/forum/viewtopic.php?id=7211
http://www.forum.simplydiscus.com/showthread.php?t=51170&highlight=carbon+leeching

 

Hi Guys,

I had a look at the threads that were referred to and some of the aspects mentioned there are correct but others are not.

Many compounds bind to activated charcoal, but bind via a process called adsorption to the carbon. Adsorption is a process where the compounds are held by the a/c but it does NOT mean they are chemically linked to the a/c. This adsorption process does mean that the compounds are held very strongly by the a/c but it does not mean that this adsorption cannot be reversed. However, this cannot be reversed easily. If the a/c is chemically intact, it has to be heated very strongly, to literally burn off the adsorbed compounds. A/c is after all a very pure form of nothing else but wood charcoal which is formed by burning. So, in principle, yes, the a/c will hold on to compounds very strongly and this cannot be reversed easily.

Now, the point that was also made about the a/c releasing compounds back into the water again, must also be interpreted with care. If a/c is kept in water long enough, it will go rotten due to decomposition by bacteria. If this happens the a/c itself is chemically altered and then it WILL release the adsorbed compounds. So, the trick is to use the a/c for a short period of time to remove specific compounds and then it should be removed and not used again.

So, Singularity is correct if you remove the activate charcoal from your tank/filter before it decomposes, but Henk is correct if the activate charcoal is simply left in the filter without replacement. I would think that a/c would start this decomposition process after about a month in a normal aquarium.

Hope this clarifies what may seem to be very opposite opinions on the matter.

Kind regards,

Dirk

 

Hmm... Thanks Dirk!

I tried putting Carbon in my cannister as one of the last stages of filtration, and I have to say that it has cleared the water quite considerably, but it still has a brown tinge, its just not so cloudy anymore.

Hopefully, it'll continue to get less brown?? Time will tell??

Cheers
Big G!

 

HI Big G,

What you must now do is to remove the a/c from the filter, and with it you will obviously be removing the tannins. If you leave it in the tank, the a/c will decompose and release the tannins again which you do not want, that is why I am advising you to remove it from the filter and thereby from the tank.

What you then do is add fresh a/c and this can then remove more of the tannins. You can do this a couple of times and then all the tannins will be gone.

Got it?

Kind regards,

Dirk

 

Yer, I got that! Thanks Dirk!

I have about another week or two before the Carbon has been in for a month, so I'll do it next water change....

One question tho....

Is there likely to be any difference in charcoal Quality when comparing the likes of the Eheim EhfiKarbon with the cheaper tub of charcoal bottled by LFS??

CHeers
Big G

 

All of the a/c types sold for aquarium use are actually quite low quality if you compare them to the a/c that is used for chemical removal in the laboratory. I am not sure if there will be a big difference in the quality of the LFS a/c vs the Eheim, but I would expect the difference to mainly be in the quantity of the tannins that can be absorbed.

BTW if you say that you have kept the a/c in the tank for two weeks and it is still brown, i.e. tannins are left and they are not getting less any more, then you can assume that the a/c is saturated and that you need to replace it. It will not be of any further benefit to keep it in there for a full month.

Kind regards,

Dirk

 

Cheeers Again Dirk,

I guess that would make sense!

I'm not sure if the AC is still removing the tannins or not, but I did notice a huge difference even after a few days. One thing I did notice tho, before placing the AC in the filter was that after a water change the water would be fairly clear, and then over a few days or so, the water would darken, presumably because of the wood still leaching, so the AC has/is being effective to a point, but I guess it is combatting an ongoing Problem?

Dunno if that made sense? lost my chain of thought half way thru!

Cheers
Big G!

 

You are perfectly correct with your deduction, I would also say that the (offending) log is leaching more tannins, so you need more a/c changes and may need them for a while yet....

Kind regards,

Dirk

 

http://cedb.asce.org/cgi/WWWdisplay.cgi?7802000

 

the link above just for some more info

 

Hi Singularity,

This is interesting information and relevant to water treatment plants where a/c is used extensively in Europe and the USA. However, this breakdown of chemicals on the a/c is critically dependent on enough oxygen which in this case is brought about by the addition of ozone (O3). We do not use ozone in our filtration systems and also the amount of oxygen that goes into fish tank filters is too low to allow these breakdown processes in the fish tank, so you have a build up of these substances and then eventually a release again as I mentioned before. Also, the quality of the a/c that is used in water purification plants is vastly superior to that used in fish tanks. So, I would still advise removal of a/c after a maximum of 4 weeks in an aquarium.

Kind regards,

Dirk