[thereds]

Hi All,

Don't know if I should panic or not so please let me know what you think. I have been testing my water every week as I have done since starting my pond. My water parameters have always been spot on and have not changed for the last 10 months apart from seeing the odd nitrite reading of 1.25 in the summer when feeding was heavy and after cutting the food back has been at 0 since. Here are my water parameters ph:8, ammonia:0, Kh:4deg or:71.2ppm, nitrite:0, nitrate:1.25(trace). The nt labs test kit I use says ideal kh is 6deg or 107ppm, the kh reading has fluctuated between 7deg to 4deg(todays reading) over the last three months. Can anyone tell my why this would happen can rain water cause this?. I know by adding baking soda I can raise the kh (adding it slowly so to not upset the ph), so what i am really asking is will my pond be ok at this level of kh or do I need to raise it by 2deg hardness to get it back to 6dh as a matter of urgency?.
Thanks for your help guys and girls
Andy

[geejay]

Hi,

The kh value can be affected/lowered in a number of ways :-

1. If your tap water has a lower value than the pond has a water change will lower it.
2. By rain water especially if your pond is open as mine is !
3. Filter bacteria need calcium carbonate but unless you are heating to a high level this shouldn't amount to much at this time of year.

Bring the kh back to 6 would be best - I use bicarb myself.

[Davej]

Hiya

Over time filter activity and any rainwater will deplete the KH.

One of the main reasons for KH depletion in winter months is a failure to do the regular jobs such as cleaning filters and changing water as frequently as they are done in the summer.

There is nothing to panic about with a KH of 4 and please don‘t reach for the bicarb just yet!!

• What’s the KH of your supply water?
• What size is the pond?
• What filtration do you have on it?

Dave