Is KH important to have at right levels?

[sealife]

I was testing ph/gh/kh of my tank water, and kh is nearly non existant. Its like that in my tap water. Everything ph and gh is fine. Was curious to how important kh is for fish health.

Thanks.

 

[Laser]

It is my understanding that a low KH can cause instability in the pH level of the water. This is because the KH (carbonate) acts as a buffer that keeps pH from fluctuating. I'm curious as to what your pH value is. I would check your pH value daily to make sure it isn't fluctuating, as any sudden changes in pH can be deadly to fish. You may wish to use crushed coral or aragonite to stabilize your KH.

 

[sealife]

Hi Laser,
Thanks for the input.

So KH is mainly used to keep a stable PH? Is that it? It has no direct benefits to fish health?

My PH is around 7.6 to 7.8 (mainly stable despite the low KH)
GH was around 5
KH was around 1 or 2, from memory.

Thanks.

 

[T1KARMANN]

You can get ph crashes at anytime with low gh or kh

If its low its best to buff it with some coral chips in your sump or filter

 

[Fishfur]

KH is carbonate hardness. Calcium, IOWs. It does have an effect, especially for inverts who need it for their shells. For some fish it's also vital, such as the Rift lake cichlids that need high carbonate levels and all fish must osmoregulate, and buffers in the water help with this too.

Calcium is not the only mineral that can act as a buffer, but it is the most common one, especially in alkaline waters. GH is general hardness, all the minerals in the water. If GH Is good then you have some other mineral, maybe magnesium, which may be doing some buffering for you.

Read up on water chemistry and buffering. It's a bit complex, but there are some very good articles, at varying levels, that you can read to help understand it.

Typically, low to no KH is associated with ph swings that can be very harmful to fish.

 

[sealife]

Ok thanks for the response guys.

Seems like I have 2 options. Either add baking soda every water change, or add some KH buffer substrate to the filter. I think I will choose adding substrate to the filter. What's the best substrate to help buffer KH, and maybe adding other healthy minerals if possible, but hardly touches PH and GH, as they seem pretty good from my tap.

Convict cichlid with bristlenose will be my fish. So i'm hoping PH wont go higher :/

 

[Fishfur]

Crushed coral will add calcium.. start with a little, add more if needed.

 

[sealife]

Done, thank you.