How do you lower the pH and water hardness of a freshwater aquarium. The pH is about 9 tested with strips and the water is VERY hard. We want Bala sharks and a blue dwarf gourami?

Answer 1

Sounds like you have a well for your tap water. I live with similar water, but not as high pH (about 8) and 150-200 hardness, and I keep these fish very successfully.

As it sounds like you already know, you have too many minerals in your water (high pH and high hardness usually go together.) The trick of adding more chemicals ("pH down"-type products) to counteract the chemicals you have doesn't really work, IMHE. You keep adding these buffer solutions as directed and the pH goes right back up. You end up with expensive chemical soup and still have too-high pH. Plus you'll get 'salt deposits' like you won't believe from all this stuff int the water!

For my water, I have had very good success with making my indoor aquarium (with balas, gouramis and other semi-aggressive community fish) planted with driftwood. The driftwood will turn the water brownish, this is not bad (I wouldn't bother removing the color with carbon, but that does work - how much stuff do you want to fool with?) For my outdoor pond I use barley straw (mostly for algae, but has a similar pH lowering effect) and peat granules (makes the water very dark.) You can put peat granules in your aquarium filter to dispense in the water. Depending on how tea-like you like your water, I believe peat (and/or enough driftwood) may work for you, at least to get tot e higher end of balas and gouramis preferred pH zone. You can also study blackwater aquariums if you really get into colored water!

The other thing you can do is get an RO unit (expensive and can be fiddly) and start with distilled water - to which you will want to add back some of your super-hard tap water to get the hardness to around 100+. You need to have hardness at least around 80 to prevent (buffer) pH swings that occur in any aquarium, especially if it is planted: the CO2 the plants gobble up in the daytime (which makes the pH rise) is actually multiplied at night when even the plants are making CO2 - and the pH can really drop. Enough hardness (Ca + Mg) in the water will dampen this swing and keep the pH pretty stable. All fish need this, whatever their preferred pH they don't appreciate major pH swings.

Definitely keep measuring your pH and hardness when you have such extreme water to start with, and are taking rather extreme measures to counteract, at least until you discover a formula that works over months.

If you want crystal clear, colorless water, go with RO. If you want to experiment with what Mother Nture can do, I would try driftwood (real wood, obviously, not resin) and peat. It will be very clear (not cloudy) but will be between weak and very strong tea color.

[As an aside, do you drink this water untreated? I do not know for sure about using softened water in an aquarium, but I think it is not a good idea. I believe the human-potable process of softening water substitutes sodium or potassium for calcium and magnesium, and I don't think this substitution is a good for fish. On the other hand, you maybe should not be drinking water this hard - check with your doctor - and if you decide to get an RO unit for your drinking water just get one big enough to handle your aquarium's needs, also.]

Good Fortune! I think you can do this.