Why are these Plants Dying?

by Dan
(New Zealand)

My friend is running a four pot hydro system which started out great, but now it's in the flowering cycle (probably around two weeks on this stage). Three of the four are wilting and look like they are dying. I was wondering what would cause this? The pH and CF readings were too high, so we changed the water and got everything right, but it has made no change.

Answer: Dan- There are a number of things that could have caused your dying plant syndrome. The wrong pH could have done it, but the more likely suspect would be the "too high" CF reading. From what I have read, I would have to guess that your plants have been over fertilized. Having the nutrient solution strength too high causes damage to the roots, which prevents the plants from taking up nutrients properly, which causes damage to the rest of the plant above ground. The damage to your plants depends on how severe the problem became....from relatively harmless leaf-tip burn to having nearly every leaf on the plant turn brown and crispy in as little as one or two days.

The good news is, this is a mistake you are likely to avoid in the future now that you have experienced it. The bad news is, once the damage has been done, there is no quick fix....your plants will take several weeks to recover (unless the damage was too severe) and your yield will be much, much smaller than it should have been.

Your problem is a common one....perhaps THE MOST common one. Many people get into hydroponic gardening not really understanding what they need to do for success. As long as you have provided adequate light, good temperature control, air exchange, air circulation, and you do not have any indoor garden pests (like mites), than the whole secret to hydroponics is maintaining your nutrient reservoir properly.

For starters, you should have a light proof nutrient reservoir, and whenever possible you should prevent any light from coming in contact with the nutrient solution. More importantly, your system should provide 3/4 to 1 gallon of nutrient solution per plant- any less and the changes in the nutrient solution strength and pH happen too quickly to stay ahead of. Even with 3/4 to 1 gallon of nutrient solution per plant available, you will still need to check (and adjust) the nutrient solution strength AND pH at least once a day.

Obviously, this means having an accurate TDS, EC, or CF meter and a pH test kit (or meter). Furthermore, you need to dump out the old nutrient solution and start over with fresh, room temperature water and nutrients every two weeks- otherwise the solution may have a nutrient imbalance and could be just as damaging to your plants as over-fertilizing them. It is important to use room temperature water for your water changes, as I have seen cold water straight from the tap "temperature shock" the roots and kill an entire garden almost overnight.

If you are not sure what nutrient solution strength your plants will tolerate, than you need to increase the nutrient solution strength slowly week after week and keep a sharp eye out for the first signs of leaf tip burn. At that point, you may want to back off the nutrient strength just a little bit and make a mental note of this as your "upper limit".

If your plants are wilting, but not actually turning brown and crispy, than you may simply have the plants too warm under your grow lights. A temperature probe at plant-top level, directly beneath your grow light, should not read more than 80 degrees (unless the garden is being supplemented with CO2, in which case 85 degrees may be OK). For more information on properly maintaining your nutrient solution, be sure to check out my how to grow hydro page. I hope this helps you figure out the problem Dan, and Happy Growing!

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(10 week update below)

Find out the cheapest and easiest ways to garden productively in this article.

Hi everyone, Jason from Jason's Indoor Guide here. When I got started with hydroponic gardening more than 24 years ago, my first garden used rockwool cubes and B.C. Nutrients....and I remember thinking to myself yeah, sure, there may be a lot of advantages to gardening with hydroponics, for example there are very few pest problems, therefore very little pest control, no weeding, no plowing or tilling the soil, no soil testing or having to add things into the garden soil, no watering the garden....but for someone who just wants to grow their own vegetables and have more control over their food supply and the quality of the food that they eat, the cost of constantly having to buy grow media and hydroponic nutrients makes this an expensive hobby for most people...

Epic Nutrient Change

I suppose when you take into consideration how much money you save NOT having to buy food at the grocery store, it is surely cheaper to grow your own food hydroponically even with the cost of high quality nutrients. Nevertheless, I didn't have a whole lot of money to work with and I needed to make my efforts as affordable and effective as possible....and in the last 24 years I HAVE learned a thing or two!

As you browse through Jason's Indoor Guide, you will notice all of the systems that I use personally are homemade systems. As I got 3 or 4 years of experience under my belt, I quickly adopted a preference to standing water systems and systems that use expanded clay pellets or lava rock, because the media is re-usable and it eliminates a huge operating expense. So once a hydroponic system is built, garden maintenance is minimal- check and adjust the nutrient solution daily, and to change it completely every 2 weeks....and the biggest operating cost is the hydroponic nutrients. (and the electric bill, lol)...

Homemade Cloner

And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient teas....like kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.

Unfortunately, I have been gardening for over 24 years and I have only just recently mastered this difficult skill....and even then, only because I happened to find a very easy to follow, high quality technique and decided to follow the instructions to the letter. I produced more high quality compost in just one week than I was able to use in a whole year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to increase the productivity of your food production efforts, while at the same time decreasing the amount of effort required to grow all of your own food, and decreasing the total cost of operating your food production system.

And when I say decrease operating costs, I mean decrease them to almost ZERO, especially if you are producing your own nutrients...

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The ultimate solution to eliminate the cost of your hydroponic nutrients: Imagine a hydroponic system that does not require you to buy any nutrients, does not require you to make your own compost, and does not require you to brew your own nutrient tea. Seriously! No cost and no effort as far as providing nutrients to your plants! Plus, at the end of the gardening cycle you harvest all of your garden vegetables, PLUS YOU HARVEST FISH from the system--->


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This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.

Produce garnden vegetables AND fish together. Eliminate fertilizer costs!

Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!

The Same System/ 10 Weeks Later!

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