We are getting our second batch of Cornish X chicks in mid July. We typically get laying cchicks in winter keep in a stock tank with a heat lamp in one end & keep in our garage. The first batch of Cornish X we got in April seemed to get to hot useing this set up, so I'm sure that is not what to use in July. Can we just put them in the tank with out a heat lamp, should I just change the heat lamp bulb to say a 40 watt incandescent ?