by Abbie
I am having pH irregularities that I can’t get under control.
2:12 am in Completed Window Farms, Getting Started, How-Tos, made from scratch (without a kit), Nutrients, Nutrition, questions, Seeking Advice, Uncategorized by Abbie
I completed my first window farm column about a month ago. I had started the seeds about two months ago but I have lost the majority of the plants I started already. I started my seeds in rockwool cubes and when they were about an inch tall I transferred them to my window farm. I left them in the rockwool cube and set the cube in a plastic grow basket with clay pellets around the cube. Up until this week I was using tap water combined with Liquid Karma by Botanicare.
The problem I am having is that the water and nutrient formula is adjusted to the correct pH in the reservoir but as it goes through my system it slowly increases. After going through the third bottle, the pH is already too high.
After doing research here and in other forums, I made the following adjustments.
1. Removed the rock wool cubes from the system completely and boiled the clay pellets. The plants are now growing in the baskets with only clay pellets. This adjustment seems to have made a slight impact on the severity of the pH increase through the system, but not enough to keep my plants alive.
2. I switched to distilled water and started to rinse the system and replace nutrient formula every other day. Again, this only made a slight impact on the pH levels. Now the pH doesn’t increase as fast, but after 10 minutes of the system running, the pH is back up above 7.5 in the reservoir.
Thankfully that I have been able to hold onto the remaining few plants by adding a few drops of lime juice to the tank every time I get a break from work (usually about 4 times during the day) but my plants are all less than 3 inches tall and the leaves are starting to turn brown on the very tips.
The remaining plants are beans (I think these could survive nuclear war they are so resilient), two tomatoes, two peppers and three basil that haven’t yet reached 2 inches tall. I lost all of the lettuce, two varieties of peppers, and my hybrid cherry tomatoes.
Anything you can suggest to help me out would be fantastic. I feel like I am taking care of a new puppy because I can’t leave my system alone for a day!
How big is the reservoir? A small reservoire goes out of wack quicker than a big one. Making the reservoire twice as big would keep your system working unattended about twice as long.
There’s such a thing as pH buffers, but i have no idea if they’re practical for hydroponics. Somebody here will know…!
Yes pH buffers will work in Hydroponics.
For instance:
http://www.generalhydroponics.com/genhydro_US/buffers.html
Ph adjustments will only be temporary.
The source of the problem is either the bottles you used (what were they used for?) or a poor quality of the pellets(might be the hardness of the water as well).
i would try to check PH while running the solution in a closed(not including the plants pots) circuit to test the tubing and materials that you used to move the solutions around.
next i would try the same circuit with new unboiled pellets and watch the ph as well.
And last i would try the pots themselves while checking the PH.
The test will be quick as PH fluctuation occurs in a matter of minutes and it will help you pinpoint exactly where the problem resides.
Good Luck
Could you add pictures to your post, of the plants? A minor pH issue shouldn’t cause the plants to respond like that that quickly, too soon for a nutrient lock-up problem, and 7.5 shouldn’t cause that anyways, it sounds more like a deficiency issue, and if you are only using one type of mixture you may be lacking. Magnesium or nitrogen deficiencies often result in necrosis from the leaf tips, I would bank on magnesium since LK has none in it, Mag is an important component of chlorophyll and if you don’t have enough older growth dies back at the tips in order for the plant to use the little Mag it has in new growth.
With that said keeping pH maintained relatively well is important, if you have a small reservoir (< 1 gal) then you should be completely emptying and refilling with fresh solution weekly in order to prevent nute lock-up.