Wet rainwater harvesting system So you may be thinking of getting more than one water tank. How do you make them more effective? One way is to link them together. Linking multiple water tanks offers greater flexibility in increasing your rainwater harvesting capacity. In fact, an often easier and cheaper way to increase your water storage tank’s capacity is to add another tank rather than replace an existing tank with a larger one.
This method fills the tanks in the system one at a time in such a way that water flows from the overflow of one tank and into the inlet (top part) of the next. Additional piping is necessary to connect overflows to inlets. It’s also important for both parts to match in size to avoid obstruction or leaks in the flow of water.
The principle of linking tanks together from the top works on gravity, which means that the overflow of the first tank in the chain has to be slightly higher than the inlet of the second tank, and so on, in a stair step pattern.
Dry rainwater harvesting systemLinking water tanks together at the top can utilise a dry system, which is when all the pipework that feeds your storage tank/s sits higher than your tank/s. Dry systems usually don't involve the use of any taps between tanks (they are free flow) which is why this is a good plumbing method for linking water tanks from the top. |
This method causes all tanks in the system to fill simultaneously and evenly. It connects storage tanks at the bottom — outlet to outlet — as opposed to an overflow to inlet connection.
It’s a good rule of thumb in this method of connecting water tanks to align all overflows, regardless of the dissimilarities in the tanks’ height.
Parallel tank system: If the tanks are the same size/height, the alignment of the overflows will be easy. Once aligned, the rest of the overflows can be capped except for one. Only one overflow is necessary assuming that there is only one downpipe equal to the size of the overflow.
Tank elevation adjustment: If the tanks are a different size/height, mount the smaller ones on a raised base so their overflows align with the overflow of the tallest tank. This means that water surfaces between tanks will align with each other when full.
Smaller tanks placed on the same level of foundation as taller water tank/s will give you a picture of water tanks whose overflows don’t line up. When this is the case, either of the following two things can happen:
1. Due to stronger pressure from smaller tanks: Smaller tanks that are weaker may burst at the seams or water may leak out of smaller and weaker tanks.
2. Depending on which overflow is capped, the water may only fill up to the height of the lowest tank.
You can continue adding another tank to your system as your space allows without losing a drop of water by doing the following:
Water tanks are connected at the bottom with rigid or flexible piping.
Linking water tanks together at their base can utilise a wet system, which is when rainwater from the roof passes through pipework that runs horizontally, usually underground or on-ground, before it enters the water tanks.
If you’ve never linked water tanks before, you may think it’s a little too complicated. But don’t worry, professional installation by a licensed plumber is often required in Australia, so it’s to your advantage to employ the knowledge and expertise of one.
Now that you have an idea how multi-tank systems are set up, what else would like to know?
Contact us for more details
Disclaimer: Please note that the points made in this article are general in nature. Since particular situations can be unique, talk to a licensed plumber to ensure the success in the installation of your multiple water tanks.
Stay ahead with the latest insights and trends that matter to you. Subscribe for regular updates directly to your inbox. Don't miss crucial information to keep you competitive!