Healthy and viable cannabis seeds have a brown color that varies from a light to a much darker shade. Some seeds have a more uniform color, while others have multiple shades and patterns of tiger stripes or turtle shells. This simple, cost-effective method is a great way to distinguish good genetics from bad genetics; they will literally sink or swim. Seeds that remain floating on the surface are more likely to be of poor quality and should be discarded.
Seeds that sink to the bottom like a botanical cannonball are probably healthy and should germinate. After inspecting the seeds with sight and touch, a quick way to separate viable seeds from bad marijuana seeds is to do a flotation test. Fill a glass with distilled water and drop the seeds you intend to germinate. It's also important to start with quality seeds, so make sure you buy seeds from a reputable seed bank.
Some cannabis strains produce a much stronger and more durable marijuana seed that can last for years and still stretch its leaves once planted. If you have marijuana seeds that have already spoiled, no amount of darkness, low humidity, or low temperature conditions will reverse it. The easiest way to get high-quality cannabis seeds is to buy them from reputable seed banks like us. Although cannabis seeds don't have such extreme longevity, growers tend to be successful growing seeds from two or three seasons ago.
Ultimately, placing seeds in the ground and watching them emerge on seedlings is the best way to identify seed quality. Yes, I agree that the best way to know that you are getting good cannabis seeds is to deal with a reputable and reliable seed bank. If the husk doesn't give way and breaks or splinters under light pressure, then your marijuana seed has spoiled and has no chance in the ground. If you purchased the seeds from an online seed bank, it's likely that they were mailed to you in a vacuum-sealed container.
Suppose you don't have time to inspect each seed for viability, germinate all of your seeds, and observe what happens. Similarly, home growers with a small amount of seeds don't risk much simply germinating all their seeds to see how things go. The large amount of variation between cannabis seeds means that even good quality seeds differ in appearance. The seeds should be stored in the dark, so cover the glass jar so that no light enters, cover the seeds inside the mason jar, or make sure the storage location is in complete darkness.
Larger caliber marijuana seeds have better germination rates, better genetics and better yields.