It is essential to calibrate using at least TWO pH buffers. These need to differ in pH by at least three pH units over the pH range being used. For nutrient solutions, pH buffer 4.0 and 7.0 are the ideal calibration standards. Some manufacturers claim that their pH meters require calibration using only pH buffer 7.0. Professional practice however, stipulates using two buffers because this will confirm or otherwise that the correct calibration “slope” is being obtained i.e. that both the electrode and meter are ranging correctly.
Let customers speak for us
from 56 reviews
<div class="dynamic-checkout__content" id="dynamic-checkout-cart" data-shopify="dynamic-checkout-cart"> <shopify-accelerated-checkout-cart wallet-configs="[{"name":"shop_pay","wallet_params":{"shopId":58123845819,"merchantName":"Growers Hub"}}]" access-token="9b818b545a8b14a14929c22f853a93f9" buyer-country="NZ" buyer-locale="en" buyer-currency="NZD" shop-id="58123845819" cart-id="bf6187223dc267179e7028372504b727" > <div class="wallet-button-wrapper"> <ul class='wallet-cart-grid wallet-cart-grid--skeleton' role="list" data-shopify-buttoncontainer="true"> <li data-testid='grid-cell' class='wallet-cart-button-container'><div class='wallet-cart-button wallet-cart-button__skeleton' role='button' disabled aria-hidden='true'> </div></li> </ul> </div> </shopify-accelerated-checkout-cart> <small id="shopify-buyer-consent" class="hidden" aria-hidden="true"> One or more of the items in your cart is a recurring or deferred purchase. By continuing, I agree to the <span id="shopify-subscription-policy-button">cancellation policy</span> and authorize you to charge my payment method at the prices, frequency and dates listed on this page until my order is fulfilled or I cancel, if permitted. </small> </div>
Secure payments
