I have a 20 gallon for my 5 month old beardie , he has a zoomed 75watt basking bulb , 10.0 reptisun , its not that hot its like 90 degrees at least , can i add a day white light bulb on the other side ? please help , dont tell my what differen light to get or any other stuff all i need help with is knowing if its okay to add a day white light on the cool side ?
It's hard to create a proper gradient in such a small tank as it is, so I'd stick with one basking light and a UVB light. At 5 months, you'll need a larger enclosure soon which will have different lighting requirements. It's important to get accurate surface temperature readings to adjust lighting so it's best to use digital thermometers with probes (one for the basking surface and one for the cool end) or an IR temp gun. Shoot for around 100-110 in the basking area and a gradient down to 75-80 or so on the other side.