any idea for increasing pH?

I have not done any water change when I started cycle them..
Nothing much, just added some plant in and put driftwood with lava rock..
Some say lava rock decrease pH value yet some say depends on the lava rock itself..

water hardness? is it GH? my GH is about 3-4degree, (not sure in what unit)
 
i had the same problem with Mopani wood. my pH crashed after a few days so i used crushed coral in the filter to raise the KH and the pH has been stable ever since.
 
maybe i didn't read correctly.. why do you "need" to have a pH of 7?

also... if driftwood is crashing your pH, you have NO buffer, as tannic acid is a very subtle nudge on the pH scale.

True lava rock is completely inert and will not cause any change in hardness or pH.. if it is, there's likely something on/in it, or its not real lava rock.
 
more important than the pH number is a stable kH.

with a gh of 3-4 I would suspect you have some real issues.

if the water you use passing thru any water softeners or filters?
 
more important than the pH number is a stable kH.

with a gh of 3-4 I would suspect you have some real issues.

if the water you use passing thru any water softeners or filters?

Good question...my water through a softener shows a higher pH (still closer to 8) but no GH or KH. I guess any slight change would send it crashing down.
 
Good question...my water through a softener shows a higher pH (still closer to 8) but no GH or KH. I guess any slight change would send it crashing down.

Water softeners remove calcium and magnesium; they replace these two ions with sodium - two Na for every Mg/Ca.

This water is deceptive for a fish keeper - it's actually higher in TDS than before softening, but reads as having very low GH/KH - zero, in theory. It looks like soft water, but it's very different from the soft water which fish actually come from which has low TDS - osmotically it's very different. It's best not to use it, unless you have fish which come from soft, slightly saline water.
 
Water softeners remove calcium and magnesium; they replace these two ions with sodium - two Na for every Mg/Ca.

This water is deceptive for a fish keeper - it's actually higher in TDS than before softening, but reads as having very low GH/KH - zero, in theory. It looks like soft water, but it's very different from the soft water which fish actually come from which has low TDS - osmotically it's very different. It's best not to use it, unless you have fish which come from soft, slightly saline water.
Hence why I do not use it.
 
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