My Berkey filter seems to have overflowed? Why is this?

When the lower chamber is partially filled up please be careful not to overfill the upper chamber as this could cause the lower chamber to overflow.

For example, if the lower chamber is 1/2 full the upper chamber can be refilled by 1/2. If the lower chamber is 1/3 full then the upper chamber can be refilled by 2/3 etc.

/* if no javascript: get back ATC button */ body:not(.spo-loaded) [data-shopify="payment-button"], body:not(.spo-loaded).template-product #AddToCart, body:not(.spo-loaded).template-product form[action="/cart/add"] [type=submit], body:not(.spo-loaded).template-collection form[action="/cart/add"] [type=submit], body:not(.spo-loaded).template-index form[action="/cart/add"] [type=submit], body:not(.spo-loaded) form[action="/cart/add"] [type=submit] {opacity: 1; pointer-events: all} body:not(.spo-loaded) form[action^="/cart"]:not([action^="/cart/add"]):not(#currency_form) button, body:not(.spo-loaded) form[action^="/cart"]:not([action^="/cart/add"]):not(#currency_form) input[type="submit"], body:not(.spo-loaded) form[action^="/cart"]:not([action^="/cart/add"]):not(#currency_form) input[type="button"], body:not(.spo-loaded) [name="checkout"], body:not(.spo-loaded) [name="goto_pp"], body:not(.spo-loaded) [name="goto_amazon_payments"] {opacity: 1; pointer-events: all}