I would not unplant the hob, but the answer to your question is yes. You did not mention if you have a high light, co2 set up, I am guessing no, because without supplementing, you will have problems. It also depends on fish load.
If you read walstads book, she repeatedly talks about the aerial advantage, that floaters and bog plants can more efficiently utilize nutrients since they can access co2. So yes they are using no3 and other nutrients. But it all depends on how your plants are doing. If the aquatic stuff is not thriving, you may need to assess what is in short supply, my guess would be nitrates.