This is another common question.  REMEMBER, the Tower Garden was designed for “Average Joe” to be able to grow nutrient dense food right outside his backdoor WITHOUT a horticultural degree or a back ground in gardening. Now lets take a look at page 10 of the Growing Guide.

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.

  1. 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.
  2. Use a dipstick.  Tower Gardener Jim Trial came up with this great idea!
  3. 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.
  4. 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.
Tower Garden Dipstick
“I thought I would share my TG dipstick. I take a reading and it tells how much solution is in the tub. I marked it in 5 gal increments. The 5gal mark is 3 inches from the end. The 10 gal mark is 6 3/8 from the end and the 15 gal mark is 8 3/4 from the end. I marked from both ends giving re two usable sticks.” – Jim Trial

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.

14 Thoughts on “How often and how much nutrients should I be adding?”

  • Since my chemistry know-how is in the “below fail” range, I came up with the following chart and depth measurement approach. Unfortunately, the spreadsheet doesn’t transfer well to this format.

    TowerTonic Supplement Chart
    H2O depth (“)* deck-top-to-H2O-surface (“)** Add # gal Add # ltrs Add Tonic A (ml) Add Tonic B (ml)
    Full: 10 3.25 20 75.7 400 400
    9.5 3.75 1.00 3.8 20 20
    9 4.25 2.00 7.6 40 40
    8.5 4.75 3.00 11.4 60 60
    8 5.25 4.00 15.1 80 80
    7.5 5.75 5.00 18.9 100 100
    7 6.25 6.00 22.7 120 120
    6.5 6.75 7.00 26.5 140 140
    6 7.25 8.00 30.3 160 160
    5.5 7.75 9.00 34.1 180 180
    5 8.25 10.00 37.9 200 200
    4.5 8.75 11.00 41.6 220 220
    4 9.25 12.00 45.4 240 240
    3.5 9.75 13.00 49.2 260 260
    3 10.25 14.00 53.0 280 280
    2.5 10.75 15.00 56.8 300 300
    2 11.25 16.00 60.6 320 320
    1.5 11.75 17.00 64.3 340 340
    1 12.25 18.00 68.1 360 360
    0.5 12.75 19.00 71.9 380 380
    0 13.25 20.00 75.7 400 400
    * staying 1-1/2″ below electrical cable cut-out
    ** topside of deck ~ 13.25” to bottom of reservoir

    Creating an easy water depth measuring device:
    Obtain a steel or plastic ruler greater than 12” long, overall, insert through the access port until the “0-inch” end bottoms out on the bottom of the tank. With a flashlight, note a “full tank” water level (probably about the 10” point), then mark the ruler where the top of the deck comes to and drill a hole through the ruler so that a rod can be inserted and the ruler can be suspended in the tank through the access hole, hitting the bottom of the tank with a rod inserted through the drilled hole and resting on the top of the deck. Then, using the above chart, we can estimate how much water and A&B tonic to add, respectively.

  • Interesting. The instruction manual I received a month ago did not have the section highlighted above – “A Tower Garden with all new plants requires a half strength of Tower Tonic….” I am wondering if that is why six of the new small plants so far have died.

    • That would not cause them to die. I’m not sure what version you have but the current guide online also states to use half strength.

  • We have been following this general method just eyeballing it and works pretty well so far. One thing to note is that for some plants like zucchini, be sure you are not skimpy with the tonic or you will get blossom rot. Tonic A contains the calcium needed to avoid this issue. Also keep your PH between 6-6.5 so the calcium will be absorbed.

  • I am in need of a Tower Garden Guide Book to help me determine how much water and nutrients to use. Thank you very much.

  • I live in Key West where the heat is about to be intense. What are good plants to grow in the summer months in tropical areas. I am having a hell of a time with Iguanas devouring everything….any ideas on that ?

    • Lettuce, greens, squash. Pretty much anything on our seedlings website except regular spinach and peas. Tomatoes will struggle to pollinate in the humid summer days too.

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