Adding baking soda to increase KH

[roxxma]

I just added 1tsp (mixed with tank water) to my 10g tank and the rasboras started freaking out, going for the surface and darting around. I did an immediate 25% water change and they seem fine now. Any ideas why they would freak like this? I did it a few days ago too (though I used a bit less baking soda, about 3/4 tsp) and the reaction wasn't as severe.

 

[Zezmo]

Are you starting with very soft water? Is that why you are raising the Kh?
The baking soda you added the first time was still in the water (unless you did a water change). A total of 1 3/4 tsp of baking soda in 10 gallons would raise your Kh about 7-9 degrees. That is a huge jump if your fish are not used to it.

 

[Devilishturtles]

Your KH skyrocketed, and your pH went crazy as well. That is why the fish acted the way they did. A large flucuation like that isn't good for them.

 

[Fishyfanatic]

I agree with DT and Zezmo. Baking soda is a tricky thing to work with beacuse it is immediate and must be done on a regular basis to maintain the proper level. Given that, I do not recommend trying to increase the pH or KH using baking soda. What is your tap pH and kH? Crushed coral is a natural way of increasing these levels and will do it slowly and safely.

 

[Elmware]

I use baking soda to raise the PH, not KH. To do this, I mix about a teaspoon with about 8 ounces of water and just add the appropiate amount, drops at a time, as needed. It's much cheaper than the solutions they sell in the stores.

Although I've been doing this for years, I've had petstore staff tell me that the Co2 can suffocate the fish, but I've never had any problems with that happening.

 

[Apocalypse_Gold]

Do you have a KH test kit? KH and pH are related. A higher KH will increase the PH. Baking soda will raise both. What was your pH before and after? I add baking soda to the RO water for my pwc, but I would be very cautious about adding it directly to the tank.

 

[roxxma]

Yeah, I test both regularly. Boston's tap water has a pH of about 7.8, KH of about 80-100 ppm and is moderately soft, with a GH of around 75 ppm. When I do 25% water changes, the pH and KH readings are very low. KH is around 20ppm and pH is around 6.0. When I added the baking soda, the KH rose for a few days and died then lowered but the pH did not. I usually do about one 25% change per week. Should I be doing it more?

 

[Fishyfanatic]

Fluctuations in the hardness and pH can be lethal to fish. It will cause them to be stressed. From your readings, your tap looks good. I wouldn't worry about adding anything to the water.

You say when you do your water changes the pH and KH are low. What do you mean? Do you mean the tank levels are low after the changes? Before the change?