How much does it cost to add antifreeze to above-ground pool lines during Ottawa fall closing?

Antifreeze for above-ground pool lines is actually a very small expense — you are typically looking at $15 to $40 for the antifreeze itself, depending on how many lines your pool has and where you buy it. Pool-grade propylene glycol antifreeze is sold at most pool supply retailers in Ottawa for around $10 to $20 per litre, and a standard above-ground pool with a basic filter setup usually needs one to two litres at most.

That said, it is worth understanding when antifreeze is actually necessary for an above-ground pool, because many Ottawa pool owners skip it entirely with no problems. Above-ground pools are generally simpler to winterize than inground pools because the plumbing lines are short, accessible, and easy to blow out completely with a shop vac or small compressor. If you thoroughly blow out and drain every line — the return, skimmer, and any additional fittings — and then plug them properly, there is often no standing water left to freeze and no need for antifreeze at all. Antifreeze is more of an insurance measure for lines where you are not fully confident all the water has been evacuated.

If you do use antifreeze, make absolutely sure you are buying pool-grade propylene glycol, not automotive antifreeze. Automotive antifreeze contains ethylene glycol, which is toxic and absolutely should not go anywhere near your pool water or plumbing. Pool antifreeze is non-toxic and specifically formulated for this purpose — it is a meaningful distinction, not just a marketing label.

The full above-ground pool closing in Ottawa should happen in late September to mid-October, before overnight temperatures are consistently dropping below freezing. The antifreeze step, if you choose to use it, comes after blowing out the lines — you pour or pump a small amount into each line before plugging it, so any residual moisture that remains cannot freeze and crack the fittings. Given that Ottawa winters regularly hit -25 to -30 degrees Celsius, that small investment is good peace of mind.