Could someone tell me what a KH buffer is and what it does?
@Auntiebarb That is a two answer question. "KH buffer" is actually two terms: KH and Buffer. First, I will tell you what a buffer is and what it does. Second, I will tell you about KH.
First, what is a buffer and what does it do...
A buffer is your pond's "shock absorbers" that helps to ensure calm, fish healthy, water chemistry by keeping your water's pH relatively stable. For fish to stay healthy, fish prefer
relative stability.
Buffer is what determines the strength of your pond's "shock absorbers", or "water's pH resistance to change". As your buffer increases, the strength of your water's "shock absorbers" increase; thus, tougher for your pH to change and this allows for a calm, fish healthy, water chemistry due to increased stability. The opposite occurs when your Buffer decreases.
Water pH is a water test metric that tells you if your water is acidic or alkaline. Water's pH has a natural tendency to change.
Generally, your pond will have a natural tendency to become acidic, although there are exceptions, due to the microorganisms and plants in your pond "cleaning" the water to make the water healthier for your fish. This "cleaning" process creates organic acids that release into the water. These organic acids will want to persuade your water's pH to decrease, become more acidic. However, if you have good strong "shock absorbers" (buffer), then these organic acids are "absorbed" by your buffer thus allowing your water's pH to resist changing.
Once your buffer "absorbs" these organic acids created by your water's "cleaning" process, then your buffer becomes weaker, decreases.
Rain is also an "organic acid" that impacts weakens your buffer.
The "cleaning" process is always occurring and always weakening your buffer.
There are natural buffers also created in your pond due to presence of plants and, as a pond ages, diverse microorganisms. However, young ponds with young/few plants creates very few natural buffers.
Second, what is KH and what does it do...
To keep this simple, KH refers to a natural salts that helps to create a buffer.
The most common of these used in ponds you are already know... Baking Soda... Exact same you likely have used in cooking...
Had water tested and advised we need a KH buffer, costing about £100 or so
@Auntiebarb You do not need to buy that £100 KH buffer the pond business is trying to tell sell you. You probably already have a KH buffer in your kitchen pantry... that is... Baking Soda.
Just as you have to be careful with dosage of Baking Soda while cooking... You have to be careful with dosage of Baking Soda for the pond.
Very easy in determining this dosage, but involves me asking you a question... If you want to know.... Just ask.
A much easier, natural KH buffer is crushed oyster shells/grit... The same grit product that is fed to egg laying hens (that is pure 100% Calcium Carbonate in the ingredient list).
@Auntiebarb Since you are in the UK, there is another excellent natural product that is better than crushed oyster shell/grit available to you... although more expensive... this is called Lithaqua, which is a mixture of crushed calcified algaes.
