I use 100% RO water in all my tanks. At first the need was not that great, I would swap out six 5 gallon jugs at the LFS to do water changes for 3 tanks. Soon I was filling jugs in the spare bathroom tub to keep up with the need as my tank count grew. This worked with a few tanks but one day I turned around and had 12. I needed a way to filter, store, and distribute at least 200 gallons of RO water per week, my Discus tank alone uses over 100 gallons throughout the week. My original post was lost due to a hacker so I am rebuilding the post, my system has evolved anyway and the post needed updated. Many thanks to RMC for helping me design and build this system.
Lets start off with the water filtration.
I use a RO unit I purchased at Premium Aquatics which is a local online reef retailer. It is a 3 stage 50 GPD unit mounted on the wall.
Input water to the RO unit comes from the output of the water softener. A PVC T was installed inline with a ball valve to turn the input water off when needed.
Since I turn the water off when needed, a flush valve was installed to prevent build up on the membrane. I flush the membrane for a few minutes each time I turn the input water on to keep the TDS down. This unit works very well, just need to turn the blue knob up to flush and sideways to make RO water.
The water exits the RO unit and enters a 55 gallon storage barrel here.
When the barrel is full a float valve actuates. This float valve in mounted towards the top of the barrel.
When the float actuates, it applies back pressure to a solenoid which shuts off the feed water.
Now that we have made the RO water, time to store it.
Initially, I used one 55 gallon drum to store my water. It has become necessary to store more water so I know have two 55 gallon drums.
To get water from one drum to the other, I use a siphon tube that looks like this.
The siphon tube goes from one drum to the other.
The T is to get the siphon started. Once the drum on the left is full, all the air is sucked out through the black tube with the check valve. The drums should stay even with their water levels as the drums fill and empty.
If the siphon breaks, the left drum that has the RO unit input line also has the shutoff float, so the water will shut off when the left drum fills. The siphon tubes extend into the drum past the pickup for the pump so theoretically the siphon will never break. (You can see the siphon tube in this picture on the right.)
Now the barrels are full of RO water, time to distribute it.
The water is pumped with a Mag-5 pump.
The pump sits in the bottom of the left barrel.
I also have a power head that is on a timer periodically churning the water to keep it from going stagnant.
The water comes out of the barrel to a distribution manifold.
At first, the water came out through a single pipe. Since I do water changes throughout the house, I had a long hose attached to it. This was impractical to use in my fish room, which is the same room the water barrels are in. I made another water changer that is better suited for my breeders. Instead of disconnecting/reconnecting the 2 water changers, I have them permanently mounted on their own leg of the manifold. On the left (yellow hose) is the water changer for the show tanks. On the right (green hose) is the water changer for the fish room.
The water changers are different sizes (1 and ½) and have different length tubes that fit the tanks better. I had to take the tops off tanks in the fish room so the 1 water changer would fit in. It was also so long that it tore up the substrate on every tank in the fish room.
Here is a picture of the 1 water changer.
Here is a picture of the ½ water changer.
Both water changers have a fill and drain line attached; they work identical, I will illustrate with the 1 water changer on my Discus tank.
The water changer is placed in the tank (notice the position of the ball valves).
The ball valve on the left (drain) is opened and the tank drains until the level drops below the strainer and the siphon breaks.
The ball valve on the left is closed, the one on the right is opened and the tank fills.
Let me know if there are any questions, I left anything out or did not explain anything thoroughly and I will update the post.