Agriculture Reference
In-Depth Information
Please monitor the pH level in your lettuce Grow Tables often.
If the pH should drop be-
low 5.8 or goes above 8.5, you create a risk of losing
(killing)
fish and plants.
Lettuce, herbs, and specialty greens (spinach, chives, basil, chard, and watercress) have
low-to- medium nutritional requirements. If you do need nutrients while adjusting pH, con-
sider using potassium hydroxide (KOH) and calcium hydroxide (CAOH2) because they do
not increase the sodium salts in the system, which are toxic to the plants and can cause tip-
burn. These bases provide essential nutrients to the lettuce plants. Potassium and calcium
help to ensure healthy plant growth.
Your basic test kit should check pH, ammonia, nitrate and nitrite. When you initially install
your fish, the ammonia will naturally increase over time; however, once there is enough
ammonia-oxidizing bacteria (AOB) in the water (week to ten days), the ammonia levels
shouldstarttodecrease. Nitrite levels shouldnowstarttoincrease thenitrite-oxidizing bac-
teria (NOB) as the AOB starts to convert the ammonia. Nitrite levels should continue to
drop to a low level depending on the balance of fish and plants in your farm. pH should de-
crease as the nitrification process makes the water more acidic. This is important so make
sure that the pH balance is as close to 7 as possible for the nitrification process to work
properly.
Monitor the pH of the water at the same time of day. Take your water sample from the
water flow going into the fish tank from the Grow Table.
After a few months in operation, your aquaponics system may see a drop in pH which
means it has become more acidic, now is the time to add some pH UP to bring the pH of
your systems back to the mid-to-high 6 pH which is a good place for your fish and plants.
More good suggestions for raising and lowering pH levels in your farm:
Remember that both ammonia and nitrite can be very toxic to fish. Nitrate is not quite as
toxic to the fish and the plants use it to produce protein and nucleic acids.
Over time, the nitrification process can cause the water to become more acidic and the
pH levels tend to go down.
If pH goes low, the water is more acidic and needs to become
more alkaline. This can be accomplished by adding pH UP which is contains Calcium Hy-
droxide (CaOH2). To adjust your pH down you can use pH Down (these are commercial
products and rated as organic) Just add a little at a time if your nutrient pH is too high in
order to lower the pH to the proper level. We recommend the product
pH Down
available
many places, but we purchase it on Amazon.com.
Start by adding a very small amount of the chemical (lower than directions suggest) into a
largebucketofwaterandthenadditslowly,overanentiredaytotheClarifier/SettlingTank
if you have one or VERY carefully to the Fish Tank WHEN THE PUMP IS RUNNING, so
