Anti freeze for a hydronic fry system? i am finally finished with my boil system. it's a hot water...

i am finally finished with my boil system. it's a hot water solar collector, next to a heat exchanger from the woodstove. it consequently travels thru the concreet slab for heat. the problem is that i'm getting mixed messages from populace about what type of anti freeze to run surrounded by it. the solar pannels will be turned off at hours of darkness and will get fundamentally cold. i was told that i obligation some special fluid for the system at $ 22.00 per gallon. i need 30 gallons! my origanal plan be to get some recycled anti freeze from a local auto salvage. any thoughts? appreciation john
Do it yourself back for flooding underground room?
Answers:    Check with your local building inspector on this.As a contractor I can not put regular sports car anti-freeze in a heat system but in our nouns it is legal for a homeowner to do this.I would strongly recommend that you hold a back flow prevention device on the domestic hose line that feed the system[this is code in most places],and if you use vehicle anti-freeze you will want one that has an atmospheric dump instead of a moment ago a double check system.Some one has suggested RV anti-freeze,never use RV anti-freeze surrounded by a heating system because it is an alcohol dais and will evaporate out of the system in a impressively short time.Now with adjectives that said I would still use the non-toxic anti-freeze for boiler systems rather than used coup¨¦ anti-freeze.Used anti-freeze could be contaminated with grease,heavy metals,and other chemicals and may also be caustic these are things that you do not want to add to a modern heating system that you enjoy spent I assume several thousand on.
Bed frame issue!please give a hand!!(keeps cave in)?
Yes there is a special anti freeze that you obligation to put in the system. don't use auto anti freeze. I give attention to that $22 a gal seems a bit elevated but what if you system froze and cracked you solar panels. I would bite the bullet and attain it in asap. Talk next to you local distribute and they will recommend what type to use.