I have heard some people have luck with placing several DampRid products in their tent but if you go that route, make sure you get the unscented type. If you can get the RH in the room where your tent is down to a reasonable RH, generally your tent will be slightly higher inside. One thing that I have found to greatly stabilize the environment is running the central AC (obviously this isn't possible for everyone) all the time and it keeps my room at 70 F and around 50% RH. I have found cheap dehumidifiers to be ineffective and a waste of money and electricity but as a last resort (I am in the US), I signed up for a Best Buy credit card, was approved, bought a $200 dehumidifier and picked it up curbside all in an hour. The expensive dehumidifiers that use a condenser are very effective and I pulled 2 gallons of water out of the air in the first 36 hours and lowered the RH in my room by 15%. I know that you don't want to run a dehumidifier, but that is the only thing that I have found to be effective after buying a $70 unit, a $50 unit, and $30 on damprid. I should also mention that I live in a finished basement so it is a constant battle for me and it may be more manageable for you with products like DampRid and more airflow.