The Planted Tank Forum - View Single Post - How to lower pH?
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post #10 of (permalink) Old 11-28-2012, 07:12 PM
Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Posts: 10,505
When the pH of the water is a concern the first questions ought to be:
What is the KH of the water?
Is the water company adding something to alter the pH?
Test the tap water:
GH, KH, TDS, pH right out of the tap, pH of some tap water that has sat out 24-48 hours.
Test the tank water:
GH, KH, TDS, pH.
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Carbonates are one of the most common buffers of pH in the water. If the KH is high then the pH will usually be high, and be difficult to alter. Adding the driftwood and seeing just a temporary result suggests the KH is high.

The proper way to alter the pH, when there are too many minerals in the water is to remove those minerals.

Fish are not actually looking for a particular pH, but the right mineral level. Almost always high pH is associated with high mineral levels that soft water fish do not like.
To keep or breed soft water fish, when your tap water is too hard, too high pH, do this:
Go buy a gallon of reverse osmosis water or distilled. From the aquarium point of view they are the same.
Test various blends of tap + RO.
25% tap + 75% RO
75% tap + 25% RO.
Test GH, KH, pH, TDS. Look first at the GH and TDS. Which is closest to what the fish want? (research the fish) Is the pH where you want it? You can now lower the pH by filtering that blend through peat moss. In this test you can add a handful of peat to a quart or a gallon of water and see where it gets you after 24 hours.
Whichever is close enough to what your fish want is what you will have to mix up each and every time. If you needed to use the peat moss, then that will have to be part of your water prep routine.
For initial set up and for water changes:
Run half a garbage can of RO, and top it off with tap water. Add dechlor.
Set up a pump to circulate the water.
Add peat moss. You could use a HOB or canister filter, if you have one, but I just put peat moss in a knee-hi stocking and use a fountain pump.
Add an aquarium heater.
Circulate the water for as long as needed until the peat moss has done its work. Overnight for sure, perhaps longer if you are reusing the peat moss. (I get several uses out of one stocking full of peat moss).

This can be a lot of work, and you might decide that keeping fish that are better suited to the tap water is a better idea.
Or you might find a system that works well for you and see this as not too much work to keep the fish that you like, but are not suited to your tap water.
Diana is offline  
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