

Pretty self-explanatory, right? But what about after that? How much and how often should you add nutrients? Let’s take a look at the label on the bottles.
So EVERY time you add water you add nutrients. 20ml of A and 20ml of B for every gallon you add.
How do I know how much water I am adding?
There are a few different ways to gauge this.
- Eye ball it. Obviously this is not very accurate but it certainly works. If the reservoir appears to be half full (and we know it has a 20 gallon capacity) then add 10 x 20ml of each, so 200ml of each.
- Use a dipstick. Tower Gardener Jim Trial came up with this great idea!
- Pre mix nutrients in 5 gallon FOOD GRADE buckets and simply top up your tower with the pre mixed nutrients. Be sure to use food grade as your nutrient water may be sat in it for sometime in the sun. You may be able to pick up these buckets at Lowes or other similar store.
- Use a TDS Meter. If you really want to know how much minerals to add you can purchase a TDS Meter. They are relatively inexpensive and you can learn more about them here. I cannot stress this enough though, it is ABSOLUTELY NOT NECESSARY!
What about when it’s hot?
Check out our post here with the low down on adding minerals in the hot summer months.
So to sum it up…
- Tower with new seedlings only – Half strength, 200ml of A and 200ml of B
- Tower with a mixture of new seedlings and mature plants – Full strength, 20ml of A and 20ml of B per gallon
- Summertime top up – Half Strength, 10ml of A and 10ml of B per gallon. Click here for more info.

A gallon of Tower Tonic (nutrients) should last the average Tower Garden (without extension) 9-12 months, depending on what you are growing. Someone who is growing tomatoes, cucumbers, squash etc will go through minerals much quicker than someone growing lettuce, greens and herbs.
Don’t own a Tower Garden yet? Learn more here.