DIY SUMP | Ryan Roach

Now that I had a good idea what a sump was for I was ready to design and build my own.

I decided I wanted a wet sump with a refugium that could double as an isolation tank for aggressive fish. Given the limited width of my stand I decided a 30 gallon long with a secondary refugium tank would work best for my set up.

Here is my initial design. The plan was to have the durso overflow from the main tank drain into 2 filter socks. I would have a bypass on the drain into the refugium and use a gate valve to control the flow. Based on my research, it is best to have a reduced flow in the refugium. Closing the gate valve slightly would give me less flow than the rest of the sump.

In the event of a power outage, I am guessing the top 2″ in of the tank will siphon back to the sump. This will depend on where your pump return lines are, but 2″ is probably a good guess. Plus the amount of water in the lines. Given all of this I have allowed for 13 gallons of back flow in the event of a power outage. This will be tested when I finally install the sump.

http://www.calculatorsoup.com/calculators/construction/tank.php

You can use this web page to help calculate your total back flow. Enter the overall length and width plus your estimated water drop.

I purchased a 30 Gallon long and had to wait a week for it to arrive. In the mean time I found a 10 Gallon tank on Kijiji I could use for the refugium. It was a standard 10 Gallon with no holes drilled in it. Based on my my design I would need a hole in the side of the tank for and overflow into the sump. Time to learn something new. I have never drilled a hole in glass before. First time for everything I guess. I picked up a diamond coated bit from home hardware. Always love an excuse for more tools. I will go into more detail on another post about actually drilling the tank, for now, I will stick to the sump.

After about a week and half, the new tank arrived and was ready to be picked up. With the new tank home I could measure for the new pieces of glass I was going to use for the baffles in the tank. The baffles should be about 1/8″-1/4″ smaller than the width the inside dimension of the tank. This will allow you to install them easily without putting any pressure on the sides of the glass. This is very important, any stress on the glass could cause a crack. If the baffles do not slide easily into place, do not force them. Either have them re-cut, or sand the edges down till they fit.

I had everything I needed to assemble the sump.

1) 10G refugium with hole drilled
2) 30G long glass tank
3) 5pcs of glass pre-cut by local glass shop
4) 1pc of Plexiglass for Sock Holder
5) 1 Tube silicone
6) 2 Filter socks

I used green painters tape to measure out the chambers and locate the baffles where I wanted them. I started at the bubble trap with the middle piece first. I used little wood pieces to hold the glass baffle off the bottom of the tank and clamps to hold the baffle level as seen below.

Here is where I made my first mistake. I was too impatient and did not let the silicon on this piece set before I tried to add another baffle. This was not a good idea. The added weight of another piece of glass caused the whole thing to shift. The silicone was everywhere. I had to pull it all apart, clean the tank and start over again.

I repeated the same process, but let the silicone set before adding the other baffles. I used 1″ x 2″ wood to space the baffles and slide clamps to hold them in place while the silicon set. With the bubble trap baffles in place time to install the filter sock holder.

I used the same technique to install the filter sock holder. For the holder itself, I used the piece of plexiglass so I could drill two 4″ holes in it to hold the socks in place. I was concerned about drilling such large holes in such a small piece of glass.

With all the baffles in place time to leave it overnight to allow all the silicon to fully cure.

Complete tank with the socks in place. Time for the water test.

minor leak between the sock chamber and the skimmer chamber

It holds approximately 16 Gallons when full and the bubble trap appears to do a good job at preventing the bubbles from entering the return chamber.

Here is the sump and the refugium in the stand.

Overall I am happy with how the sump turned out. A few mistakes, but in the end I have a sump that costs less than half what one would cost from my local fish store.

Since I decided to design and make my own sump. I figured I better do some research and learn exactly what they are used for and why we bother to install them on tanks.

Like everything else in this hobby there are a multitude of opinions on sumps. Some believe we don’t need them, and some swear by them. From what I gathered it is possible to have a healthy thriving tank without a sump. They are not required and your tank will survive without it, but lets examine what sumps are and some of the many benefits..

According to Greg Taylor at www.reefkeeping.com a sump is “A tank or container placed lower than, and which receives drainage from, the display aquarium”

Sounds pretty straight forward. But what’s the point, why bother with the extra equipment or the hassle of all the plumbing.

There can be many benefits to installing a sump. The added water volume can offset some of those missed water changes. You can hide equipment in the sump cleaning up your display tank. It can simplify water changes. A sump helps aerate the water and can keep the display tank water level consistent since evaporation happens in the sump. These sounded like good reasons to me.

The added water volume allows the system to be more stable. This was part of the reason I went with a larger tank. This can help avoid a tank crash due to inexperience of overfeeding, or poor tank maintenance. Both of which I will likely be guilty of over the next few months. Hiding equipment in the sump will clean up the display tank and give it a more natural look. Lets face it, a HOB (hang on back) refugium can be an eyesore to look at, or the heater cords swaying in the breeze of your tank does not give the feeling of “natural reef” system. All these items can be tucked away in the sump under the tank, away from view. The added water aeration is also a bonus for the fish, if you need to use a bubble stone it can be added to the sump. The fish will thank you for added oxygen and all those little bubbles can be left to float around in your sump tank and not your main tank. Another annoying thing about a giant tank of water, is evaporation. I loose a lot of water from my 55G freshwater tank on a daily basis, more in the winter when the air is dryer. This takes away from the look of the tank. Adding a sump with an overflow and return pump can eliminate this from the display tank. As water evaporates, the sump level lowers, not the main tank.

Another nice feature of a sump tank is the ability to add water treatments through the sump tank. By adding these items to the sump tank they are slower to mix with the water in the main tank. This will allow for a more gradual and even treatment. It will also help reduce the shock to your corrals and fish.

If your sump has a refugium area it can be used to add additional rock and sand for greater surface area to grow beneficial bacteria. It is also a great place to grow algae. This algae will help control the phosphate and nitrate levels in your tank by absorbing it as a food source to grow. A great way to naturally prevent algae from growing in your main tank. Refugiums can be also used as a safe haven to grow Copepods as a natural food source for Mandarins or other fish.

Sizing a sump depends on how large your tank is. There is no hard formula that I could find to give you a minimum size. The general consensus is “as large as possible”, quoted from multiple forums and websites I reviewed. One general rule I did find was that your refugium should be approximately 10% of the total tank volume. I have a 125 Gallon tank, so my refugium should be roughly 12.5 Gallons. The Size will also depend on the equipment you want to keep. If you have a skimmer, a few reactors, heaters probes, ect. You will need a sump that can accommodate all these items. Again, going with a sump that is “as big as will fit” in your stand will help to accommodate all your equipment.

There are a multitude of sump designs. All you have to do is Google “sump design” and you will see what I mean. If you wanted to make your own. A DIY sump could be made from almost anything that can hold water. There are sumps made from a 5 gallon pails to 50 gallon water troughs. A little plumbing, a return pump and some imagination and you could have a sump from just about anything.

Ryan Roach

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