These are cheaper than MarsAqua, but a bit better IMO. They are almost identical to ViparSpectra unit (difference being that this one has 2 UV lights, and 2 red LEDs are in a bit of a different spot)
I got these, but havent tried them yet, as I havent started with setup.
https://www.ebay.com/itm/BLOOMSPECT-...e/332782539617
PS: Dont trust "last one" as it said the same thing when I bought mine. 2 more sold after as you can see.