Yes , your water temp is ok for a young adult. Recommended by reputable site’s is 75*-80* the 80* for babies 1 year and under for the rapid the growing and minimum of 75* for adults. Basking temp at least 10* above water temp to a max in the range of 90* then 92* for some species.
Hers a video about UVB readings :
https://www.bing.com/videos/search?q=UV ... ORM=VRDGARHere’s a link to Mega Rays , if you go with one use there coupon to save money. Also for good info click on all articles and videos they have :
https://www.reptileuv.com/shop/index.ph ... 7542eba405UVB bulbs came a long way , first just CFL’s with little to "no" heat then over some years to mercury vapor. That's why supplemental heat is needed for some types of UVB bulbs. Must learn all you can , some even say full spectrum but don’t offer the range of full spectrum or the amount of micro watts (uW/cm²) their bulb produce. A reputable company will for a maximum and minimum distances because each reptile has there own requirements on UVB rays ( uW/cm²) . What some call reading’s are no-were usable UVB rays for a aquatic turtle. They just state reptile bulb , beware of them. Improper light can hurt/burn a turtles eyes. That’s why I asked about which eye lid’s are open or closed when under your light. The upper can close all the way down , lower can go all the way up and then under both of them a clear ish nictitating membrane. They use that when in dirty water or very bright light. You can just make out the pupil when nictitating closed , almost looks like it has a cataract. When all open eye looks nice and clear and bright looking. Nature is wonderful !
Then to really get into UVB light there’s the “Ferguson Zone” , that is great to use to but requires a special meter. There are many light meters . Would cost way too much to make one meter to do all readings and then no one would buy them.
Here’s a link to a good site :
https://www.solarmeter.com/Watch this for Ferguson Zone :
https://www.youtube.com/watch?v=cklUCpqsBp0I just use a 6.2 UVB meter all your need unless you have a deep pockets to get others too. With the 6.2 all I want is to know when UVB ray's get too low. I get 18 months of usable UVB rays for a Mega Ray. You would have to buy a couple to several other brands for that life span , making the Mega Rays cheaper over all.
And yes I recommend Mega Rays , the heat it put out is usable. Remember to have a good UVB bulb last it must have a little lower heat to it. The Reptile UV site explains that more. If I go to the mimium distance my basking dock get's up to 97* so my distance is 16" and get a 91* reading using a "IR" type thermometer , what I and Piggley want.