The easiest way to fill or top up an aquaponics system is by using ordinary outside tap. Here is what you need to know about using scheme tap water in an aquaponics system.
The chlorine present in tap water is potentially harmful to your fish and the bacteria colonies living in your growbed (Microbiology). There are methods of dechlorination including, letting the water sit for a few days to allow the chlorine to evaporate, using a chlorine filter or even buying cleaned pond water.
I personally like to keep things as natural as possible so dechlorinates are out of the question for me.
When filling up the system for the first time you’ll need to allow at least 72 hours for the chlorine to evaporate from the system before adding anything with bacteria, this include your cycling nutrients. A week would be better. Run the pumps during this time to aid in the evaporation of the chlorine.
During normal operation, your system will lose water due to evaporation with the rate of evaporation depending on the time of year, weather conditions, or whether the tank has a cover or is open aired. You can let the water level drop a quarter of the volume of the fish tank before you need to top it up. If you ever need to top up more than half of the tank you must do it in batches over a couple of days to a week. Slowly adding until it is at its capacity.
Filtered tap water is suitable to be used right from the tap if you need to top up the level in your fish tank. However, only ever add filtered tap water directly to the fish tank.
Never apply tap water to the vegetable garden filter as the possible chlorine in the tap water can kill off bacteria colonies. Make sure to have a reputable and certified CHLORINE FILTRATION SYSTEM.
As long as you don’t top up any more than a quarter of the volume of the tank over 3-4 days and fill up only via the fish tank then the system and the fish will be fine.
However it is worth mentioning that by adding new water to your system you are likely adding water of a different pH to the water in your system. If you are topping up a quarter or more of the volume of your system you are likely to cause a pH spike in your system. So super slow additions over a week or more I advise.
The pH of the water is important for many reasons.
All fish have a preferred pH range. pH can affect fish health, mainly due to its effect on increasing ammonia becomes more toxic at higher pH.
pH has a huge impact on the plants, more specifically, the ability of the plants to take nutrients from the water. At higher pH, the plants become very poor at being able to extract the nutrients in the system. Your system might be bursting with nutrients; however at a high pH the plants may be unable to use them! NUTRIENT LOCK OUT.
You are looking for a pH of around 7.0 as optimum for the plants (some species prefer higher or lower pH however 7.0 is good concession for both plants and fish). The process of converting fish waste to plant food will naturally lower the pH in mature systems, however in early establishment the system does not have enough bacteria to make a difference to pH (systems less than 6months old).
Before you top up your fish tank, take a water test reading – after your top up take the reading again. ALWAYS ONLY USE A FRESH WATER TESTING KIT
If the reading is a full unit up or down on the pH scale, fill a bucket of water from the water source (filtered tap), let it sit for a day and take a pH test. This way you will be aware of the pH of the water you are introducing into the system and make adjustments if necessary (another post about this coming soon!).
Blessed LOVE Ras Mark SUBURBAN FARMER.