Water Culture / Water Hardness getting a thread going!

[Ben]

Hi all



Water culture in the Zebrafish Research Setting

We have a low KH of 2 degrees in our system and have been told that it would be best for fish health and water stability if we increase this to 4.  What KH is your system? 

We have put coral in our system already which is said to increase KH and GH but this only resulted in a rise of GH from 4 to 6 and nothing to the KH.

Sodium Bicarbonate is said to raise KH only?, we use this to stabilize our PH which is currently 7.4 on the system.

If i raise the PH will that in turn raise the KH?  ( it is said that the lower the PH scale is better as any ammonia build up will be less toxic!)

Our system is big for the amount of fish we have and has readings of zero for ammonia.  Should we decrease the water exchange rate from 10% to a lower exchange, would this have an effect on the KH?


How can i raise the KH of my system?

Ben

[bruce]

Hi Ben,
I think 10% is probably a touch excessive at the moment. I'm guessing that you are still at under a couple of 1,000 animals or so at this stage in a few thousand litres of water.

Keep in mind that r.o. that you are using for make up water has 0 dKh, so you will be diluting down any buffering capacity that the system has, with the daily changes.

The drum filter cleaning will still be covered quite easily even if you were to drop the % down to 2 or 3%.
Have a look at your nitrate level to give you a good guideline of whether your waterchanges are coping with your bioload.

[Ben]

Hi Bruce

thanks for your response.

You have Confirmed what i was thinking


I will drop the water exchange and keep a close eye on the bio load. 

Ben