When you cut your plant at the root (full harvest), you will need a new biodegradable sponge for the plant to come after. A new sponge is recommended because you have organic material in the used pod, which may rot and lead to unwanted problems for the other plants in Herbert. Should something like this happen, you can easily change the entire water of the system.
At the beginning mainly in our online shop. We plan a subscription, where we would deliver all consumables (sponges, seeds & fertilizer) to your home at about 10€/11$ per month. The single items will be available as well: sponge packs with 10,20 or 30 units, bio mineral fertilizer and different seed mixes.
We took a lot of effort into soundproofing when designing Herbert. We did not measure the exact noise generation yet but from our personal estimation we would say that it should be around 30-40dB. You would have to place your ear near the front cover in order to check if the pump is running.