Need help Identifying a Pool Part

[shananigans]

Hi All - Preparing to open our new saltwater pool for the first time this spring....thought we had all the steps down and all the parts labeled and identified, but am stumped by one part. I've attached a photo - can anyone tell me what this part is (red arrow pointing to it) - it honestly looks like a clear tube filled with birdseed lol? Also, does this play any role in either winterization or opening? Thanks so much for helping out this newbie!

ETA:
In ground, 28,000 gallon

• (1) Hayward Tri Star 1.5hp Filtration Pump.
•  (1) Hayward Cartridge Filter C-4030
•  (1) Aquarite® Salt Chlorination system w/T15
•  (1) 140,000 BTU Hayward Low Ambient heat pump.

 

[ajw22]

The wire connected to the top of your birdseed container looks like it is connected to your bonding grid.

It is a sacrificial anode.

Sacrificial Zinc Anode | Sacrificial Anode for Salt Water Installation

A sacrificial zinc anode for salt water pools will help protect metal in your salt water pool from corrosion and other damage.

www.saltwaterpoolandspa.com

 

[shananigans]

Thanks for the quick response and helpful link Allen - that is it!