How to make my tap water safe?

[quinnARIUM]

Right now my tap water has the water parameters:
Total hardness (GH): 25
Nitrate: 0
Nitrite: 0
Cl: 0.5
Carbonate (KH): 15
pH: 6.4

And my tank:
Total hardness (GH): 50
Nitrate: 0
Nitrite: 0
Cl: 0
Carbonate (KH): 20
pH: 6.4

As you can see I have very acidic water that isn't to chlorinated. In my opinion this works really well for most Amazonian fish but I understand that low pHs without a lot of buffer can fluctuate too easily.

What should additives should I use to balance my tank? What schedule should I dose them? I would like to try to maintain a low pH since it suits the discus fish I would like to purchase soon and keeps ammonia very harmless.

 

[Naughts]

No additives, just regular water changes with a good dechlorinator to keep the parameters stable. 50%+ for the water changes each week, once you have discus 30% 2x/week may be more suitable.

 

[StevenF]

mamy fish and invertibrites and plants do very well in water with a PH of 6. As to buffering you already have a KH of 20 so buffering isn't needed. PH is not your issue.

You issue is your GH Your tap water GH is 25 while your tank is 50. A big difference. This would indicate to me that you are not doing enough water changes. IYou should do a water change once a week. If you are then you might not be replacing enough water during the water change. I would slowly increase your water change schedule to get the GH number down closer to your Tap GH.

 

[itiwhetu]

I would be making sure that you have a natural base with a slightly alkaline component to it. That will naturally give your tank some hardness stability, but shouldn't alter your pH by much. Regular water changes going forward.

 

[Byron]

As you can see I have very acidic water that isn't to chlorinated. In my opinion this works really well for most Amazonian fish but I understand that low pHs without a lot of buffer can fluctuate too easily.

What should additives should I use to balance my tank? What schedule should I dose them? I would like to try to maintain a low pH since it suits the discus fish I would like to purchase soon and keeps ammonia very harmless.

Others have already noted most of what I will suggest, but this is an important issue. You do not ever want to be relying on additives/chemicals to somehow influence parameters (GH, KH and pH). The biological system will establish itself and be stable, and if this is achieved from the source water parameters, all the better. There is much less, in fact really nothing, that can go wrong--if you are regular with maintenance (weekly water changes, filter kept clean, and not overstocking/not overfeeding.

As soon as you add "x" to provide buffering or whatever, you are interfering with the natural biological system and this is where trouble occurs. I agree you should look into the GH doubling; this could be due to the substrate or rock if these are calcareous. It sometimes occurs from plant additives (no mention is made of live plants or any fertilizers). I assume the GH and KH are in mg/l (same as ppm), not dH and dKH, in which case you have very soft water and that is fine.

It is true that the pH will likely lower over time, but it will still stabilize at some level in reference to the GH, KH, CO2, etc. The so-called "advice" one frequently sees that buffering is needed has no factual relevance when dealing with soft water fish species. Any fish from South America with a very few exceptions will be designed by evolution to function best in water that is basically zero GH and KH with an acidic pH. It is when aquarists with soft water begin keeping hard water species that trouble occurs and buffering is critical, but not if you stay with soft water species.

My tanks have been running for years with zero GH/KH and an acidic pH, and I let the pH settle where it likes. Obviously I only keep soft and very soft water species. My plants also have no issues, though the lack of calcium does mean certain plants like Vallisneria do not do all that well unless I add it, but the fish don't need it so I don't.

 

[quinnARIUM]

Thank you for the very informational replies! I do not add any additives or ferts to my planted tank and it things have been going smoothly so thanks for the reinforcement. I will do more water changes to maintain the GH, I have not done one is some time since there are very few fish in the tank.