Backyard Aquaponics
A place to discuss aquaponics

Here’s the deal,

Utah State University is working on starting its second aquaponics system. As part of the class, we are trying to find out ideal level for the different components of the system.
So, what level of alkalinity is the best balance for an aquaponics system? How do you raise or lower alkalinity? How important is it to keep an eye on alkalinity?

We appreciate any help!

It's very important to keep an eye on alkalinity,because when the PH drops too fast it will shock the fish (or worse) & kill the bacteria.Temperature plays a big role in how fast the bacteria multiply & give off more acid hence running it down faster.

The more the better but it's very difficult to have high KH without high GH making the PH too high.You want a minimum of 75ppm of alkalinity in the system to hold the PH in place but this will run down fast,again it depends on a lot of factors,like temperature.


To raise it you need Carbonates or Bicarbonates,Calcium Carbonate is a popular one because there are natural sources available & abundance.It's also adding Calcium to the system.Another popular one is Potassium Carbonate / Bicarbonate,but these are synthetic.Another popular one is Magnesium Carbonate which there are natural sources too.But adding these may cause nutrient lockout problems.
To lower the alkalinity,you could also use a number of things,obviously acid,Phosphoric,Hydrochloric & Nitric (food grade of course).Adding a lot of those could cause toxicity problems.Another method to lower alkalinity is to use pure water (0ppm TDS).