Lemon Juice in Aquaponics Systems
Lots of people do it, and all live to regret it. Everyone wants to run their system in a pH range that is ideal for nutrient availability to their plants, however, most systems end up having a rather high pH on the front end, during system establishment.
When folks measure their pH and see that it’s high, their first response is to ask “How do I lower it?” and often “What can I add to my system to lower pH organically or naturally?” This is a perfectly reasonable question, and one that many folks ask.
The answer to this question is that adding acids to your system is not the most cost effective way to bring your pH down.
The Right Way to Lower pH
The best possible way is to establish a good nitrification cycle and feed your way out of your high pH range, or install an RO filter to remove the carbonates entering your system and keeping your pH high.
This is the right way to do it.
Lemon juice is the wrong way.
Lemon Juice Kills Bacteria
You see, the primary acid in lemon juice is citric acid, which is also a great antimicrobial compound. So, when you add lemon juice to your system, you run the risk of killing your nitrifying bacteria- the same bacterial that not only support your entire system, but also offer the ability to get out of the high-pH hole. So, next time, instead of adding acid to your system (appropriate in VERY few cases), simply be patient, or shell out the money for an RO filter. These are the two best things you can do to correct a problem with high pH. * *Note: Nitrification is dependent on Biological Surface Area (BSA; see the BSA post), so if you do plan on being patient and waiting out your pH issue, first make sure you have lots of BSA in your system!