Internal trench waterproof system just installed in basement that includes some new concrete in July. Will a dehumidifier hinder optimal curing of the concrete and for how long? Also should I spray the new concrete with water every day to cure stonger?
Humidity usually helps prevent the rapid drying of the concrete and prevent premature cracks on the concrete surface. However, a household dehumidifier would not have the power to dry the air to the extent that harms the fresh concrete, so I wouldn't worry about running a humidifier to keep household humidity low. But water curing is a good idea, depending on the thickness of the concrete and the weather, it usually requires 3 - 7 days.
Instead of water curing (could be undesirable), a water-soluble curing compound applied after concreting can be considered, or simply cover the fresh concrete with plastic sheeting has been proven to be effective.
You should look at the instructions on the packaging. Most concrete recommend spraying water on it for a few days. Some just suggest covering the fresh concrete with a plastic drop cloth for a few days. Some just say to let it dry and be done with it. If this was poured by a company and no instructions are available, go with the spraying
I wouldn't worry about a humidifier affecting the drying but if it helps you sleep at night, cover the concrete with the dropcloth.