Is It Possible To Lower Alkalinity?

[KrystaK]

My tank has a high pH. It seems that no matter what I've done over the months nothing has been able to change it; if it's trying chemicals or bog wood.
I had my water tested at the LFS today and they said all my stats were reasonable except pH and alkalinity; which was at 400 (My pH is 8, but the lady agreed it was on the high side, considering I don't want African Cichlids) (Hardness was at about 200, which apparently is reasonable)
 
So this led me to do some research on alkalinity (I've heard of it before, but never really care about as I didn't understand it.)
Anyways to my understanding, alkalinity is the presence of ions in the water such as hydroxide and bicarbonate. These ions are very good buffers, which means that they don't allow change from a stable pH. (Correct me if I'm wrong, I'm sure my definition is much to simple, but it provides a base on which to build at least.)
 
If I wanted to lower my pH, I need to lower the alkalinity in the tank first. 
This is where you guys come in; is this possible? I've been drifting around google and all the sites I look at that mention alkalinity all say the same general things, but don't really tell me what I want to know. Which is; is it possible to lower the alkalinity?. If so, how? If not, why? 

 

[TwoTankAmin]

Read here first: http/fins.actwin.com/mirror/begin-chem.html
 
Mix ro water with your tap water to lower the alkalinity and make it softer as well. That will facilitate the lowering of the pH. How you do that is up to you. Most ways will stain the water. Ways that won't can be a bit costly.

 

[Tongue_Flicker]

Adding driftwoods, mopani wood or cooled boiled water from leaves safe to fish (i know there's a list somewhere) can add tannins/tannic acid that softens water pH.

 

[CrimsonBoli]

Your LFS should sell RO water if you cant produce it yourself. Over here its £0.25 /L which I think is fairly reasonable?

 

[the_lock_man]

Adding driftwoods, mopani wood or cooled boiled water from leaves safe to fish (i know there's a list somewhere) can add tannins/tannic acid that softens water pH.

 
If you have very hard water, adding wood will not budge the pH - as stated above, the bicarbonate ions, etc., buffer the pH, and it basically doesn't budge. To lower the pH, you need to first lower the hardness - which is basically what TTA said.