Before I was able to borrow a Par meter I used a foot candle meter. If you can find coralvue luminbright pendant you be amazed how well they reflect the light into your tank.
https://www.coralvue.com/lumen-bright-mini-metal-halide-reflector
![300 with mh on R.jpg 300 with mh on R.jpg](https://www.reef2reef.com/data/attachments/936/936018-5d7c2c4d295971a23303e743d2d8f20c.jpg)
https://www.coralvue.com/lumen-bright-mini-metal-halide-reflector