Been using this product for over 2 months now without any issues. It doesn't stink up your loop compared to swiftech hydrx and it comes clear as distilled water so you can mix it with any sort of coloring you would prefer.
This has ethylene glycol in it. EG serves as a lubricant for your pump, a corrosion inhibitor, and is highly toxic so it is also a biocide (no algae). I know someone else said it doesn't stink up your loop like hydrx but they are wrong. The smell is the EG not something else swiftech put in the coolant. I would recommend this over hydrx though because it doesn't have UV reactive particles or dye that can separate out. Use this with distilled water and if you need color use food coloring (will not separate out and clog water blocks). Don't think you need a corrosion inhibitor because your loop is all copper and brass? Think again... low quality plating on fittings, TIN solder in your radiator, and the mistake of using a kill coil can all lead to some very disastrous loop issues. W/ EG you don't use a silver kill coil, if your fittings plating fails the EG will keep it from reacting, and it will keep the solder in your radiator from corroding or causing your waterblock to corrode.
I've been using this in multiple builds so far and only one showed some algua build-up. Great for the money since it's a concentrate and you can buy distilled water for 2-3$/gallon at any pharmacy. Strongly recommended on every single loop.
After a month of use, I haven't seen any issues in the additive, neither in the loop. Simple and clean to use with distilled water and provide safety that your loop will stay clean as long as possible.