If you own your home, use a Home Equity Line of Credit (HELOC). It’s a credit card attached to your house. Sounds scary. But the interest is tax-deductible. Seriously. Uncle Sam says “congrats on your clean water.” You write it off.
Risk: Don’t go wild. Use it for the UV system. Not a jet ski. A jet ski doesn’t filter giardia. A UV system does. Priorities.