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GoldnTexas

Mopani Wood

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Was thinking about getting a medium piece of mopani to attach some Java fern to eventually but I've been reading up a lot about it releasing tannins. These are great for certain species, but how will goldfish react to them? I was planning on getting a piece probably too big to boil but will soak for up to a month in a plastic storage tub changing water often. Anybody with experience? Or anybody know of other types of wood that leech less tannins? Thanks in advance!

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Tannins aren't a big deal in my opinion. Sometimes they can muck with your pH, but I've never seen it happen and have had water turn tea coloured several times. Best way to deal with them is to soak the wood for a few weeks beforehand. Another option is to boil it for a few hours.

Manzanita, redmoor root and ironwood are good varieties, to name a few. The first two don't usually release tannins either. :)

Edited by dan in aus

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I've had several pieces of Mopani and they didn't affect my pH, but they did brown the water for a while.  To avoid or lessen this, you can soak them in a bucket of water and do daily water changes until the water starts to run clear.  

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pH flux from tannins released from wood depends on a few things: volume of water in ratio to amount of wood, as well as your water's hardness.  The harder the water the more it buffers against the acidic tannins.  But medium to soft water can have a rapid drop in pH (especially if you add a lot of wood).

 

I've used mopani (as well as manzanita and ghost wood), boiling the [censor] out of it really helps (it puts a fast forward on the whole 'soak it for months' process).  If its smell enough to fit in a big pot boil on the stove when you're home.  I do 1 hour boil, pour off water, refill (rotate wood if its sticking out of the pot a bit) and boil again.  I did 12+ hours of boiling for a mopani piece I put in a 10g tank, no tannins or pH swing/drop afterwards. 

 

In a small tank full of woods it dropped my pH below the lowest reading on api test kit in their tanks. I have 75.pH 179 ppm gh and 89..5 kh from the tap (did not boil wood first).

 

My ghostwood was huge so I used a 16" metal feeder pail and propane burner (used 2 tanks of propane) to boil it.. didn't get a thorough enough boil so it dropped pH to 6.6 ish for a month.  Lots of water changes helped get it back to normal as it removes the tannins. 

 

Some people also use Seachm Purigen to deal with tannins/tea stained water.  I've not tried it though.

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I use spider wood which also leeches tannins, so I boil the wood for several hours. When I get a piece that is too big for my biggest pot, I boil a portion of it then three hours or more later turn it around and boil the other part for the same amount of time. Lots of boiling. My understanding is that spider wood doesn't leach as much as mopani. I think with spider wood I could have gotten away with just a couple of hours of boiling.

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I always boiled mine just to play it safe.

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I use spider wood which also leeches tannins, so I boil the wood for several hours. When I get a piece that is too big for my biggest pot, I boil a portion of it then three hours or more later turn it around and boil the other part for the same amount of time. Lots of boiling. My understanding is that spider wood doesn't leach as much as mopani. I think with spider wood I could have gotten away with just a couple of hours of boiling.

I believe you're correct and mopani as one of the most tannin heavy(releasing) woods common to the aquarium trade. But at least mopani sinks instantly (unlike ghostwood, spiderwood, or mazanita).  Of course after a lot of boiling most woods will sink ^^

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I bought a small piece of mopani wood at PetSmart and boiled it several times in a large pot to leach out the tannins. It took about 6 rounds of boiling before the water ran clear. I've had the wood in my tank for over a year and it hasn't colored the water at all.

 

The two biggest problems I have with the mopani wood is that it permanently stained the pot I used to boil it, and the wood is rough on the back so the brown algae is much harder to scrub off during water changes.

 

Otherwise, I really like the look of the natural wood in the tank. Even though it's a small piece, it sinks and sits easily on the bottom of the tank where I place it in front of the airstone.

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