low kh

[cazandchris]

Hi Tom
Have quizzed you before re low kh here in Sydney.
Now have 4 discus in 40g tank. Twice weekly w/c. I add Barr gh booster to about gh5 . tank water goes down to zero KH fairly quickly. Tap water is kh 1.
Ph at end of day is 5.6..
Is it risky letting the KH stay so low in the discus co2 tank.... or should I boost KH to 2 or 3 and if so how do I maintain the artificial KH for want of a better word without stressing fish at w/c time?
Do I just add 1 teaspoon of baking soda after every 50%w/c for example..... or do i need to be more scientific than that...
cheers
chris

 

[Tom Barr]

1 Teaspoon is plenty.
I think the CO2 is low if the KH is all gone so fast after.
Plants will use KH if there's not much CO2.
So that might be where the KH is going.

Discus come from places with no real KH, so it's not going to harm them at all.
You just will not be able to measure CO2 using KH/pH.



Regards,
Tom Barr

 

[cazandchris]

Thanks Tom
If I want to add lets say 1/2 teaspoon of baking soda then do I just drop some in with GH booster after water change? Is this a safe way to go with discus? ie kh will change a small amount quickly after w/c..
cheers
chris

 

[Tom Barr]

Sure, that ought to be fine.
You should see a slight build up of Kh over time, then level out.


Regards,
Tom Barr