sMerits are there on your account to spend. They wont be remove unless theymos adds a "decay sMerit" system to the forum.
I saw your merit history and there is one merit that has been awarded to you in the last 4months.
June 13, 2018, 09:43:31 PM: 1 from odolvlobo for Re: Evolution of currencies
If you had spent all your sMerits prior to this then this one merit will contribute to a 0.5 sMerit on your account. That much cannot be sent. It needs to be at least 1 sMerit to be able to send. Thats the minimum amount.
I think this should clear your question and if it does please lock the thread to prevent unnecessary comments after this.