DIY Bell Siphon for Ebb and Flow Aquaponics with 75 gallon Aquarium

I had a rough week this last week, so I decided I needed to build something. So I built a bell siphon for an ebb and flow grow bed (also called Flood and Drain grow bed_ for the 75 gallon fish tank in the living room. This will allow me to grow plants using the fish water. This is pretty cool, as it means that the plants will remove the nitrate buildup which is the primary reason people need to do partial water changed in their aquariums.

My 75 gallon aquarium in the living room before I added the  aquaponics component to it.
My 75 gallon aquarium in the living room before I added the aquaponics component to it.

The whole thing will be completely automated and cost me less then $50 including buying tools and leaves me with lots of spare parts. 3 pieces of 4 foot PVC pipe with only about 6 inches cut off of each, so I have enough of this to make half a dozen more if I wanted.

A bell siphon is a passive autosiphon device that allows a continuous flow of water into a container to periodically be drained completely out of the container. This is good because it allows me to have my Eheim aquarium canister filter output into the grow bed, and the bell siphon will flush the bed regularly, aerating the plant roots.

To start, I assembled a drain out of plumbing PVC parts. This consists of a stand pipe to go inside the aquarium, 2 fittings to work as a bulkhead nipple, and an offset to route the water around the aquarium lid into the drain tube.

Showing where the tub will go.
Showing where the tub will go.

My wife let me buy the parts and take over the 75 gallon aquarium in the living room with my plants. She had it decorated really nicely, but my plant stand was evicted from its spot to make space in the baby room. They needed a place to go, and I used this as an excuse to work on the aquaponics setup.

Katie and Bella Supervising
Katie and Bella Supervising

I started fiddling with the pieces I had bought and realized that I didn’t get all the right pieces I wanted, but I had gotten enough to make it work.

The bottom half of the bulkhead and the 90 degree angle.
The bottom half of the bulkhead and the 90 degree angle. The angle will provide the offset to go around the tank lid.
A bit of glue oozing into the PVC joint.
A bit of glue oozing into the joint. This needs to be cleaned out to provide less water flow resistance.

I used an antique brace with an adjustable size bit to cut the hole in the plastic. Basically, the edge of the bit would score the plastic. It worked great, except for the plastic cracking.  I siliconed it up, but, to my great annoyance, the silicone was old and didn’t set. I had to clean it off and go get a new tube and try again.

Cracked grow bed bottom
Oohps! I cracked the bottom of the grow bed. No worries, a bit of silicone will fix it right up!

After two days of futzing with this thing, I finally got a dried silicone seal around the stand pipe and over the crack. The grow bed will sit on top of my 75 gallon aquarium so I designed the drain to offset around the aquarium lid. No drilling holes in the lid… yet…

The stand pipe drain for the ebb and flow hydroponics grow bed.
The stand pipe drain assembled and ready to seal in place with silicone

I then made the bell siphon which sets over the stand pipe. I again used my brace and a smaller bit to drill holes in the 3″ PVC pipe. This made it much easier to cut with the PVC cutters I had bought. The 3 inch was just to thick for me to cut otherwise.

PVC holes drilled with a brace and bit
Using a brace and bit to drill holes in the PVC where I will cut it to make the bell siphon.
The bottom of the bell siphon
The notches in the bottom of the bell siphon allows water to flow in easily.

A slight design flaw (um, the drain) left me with a grow bed that wouldn’t sit on the aquarium stand lid. A bit of scrounging around, and I found a plastic crate that I am using. The grow bed sits on the crate, which leaves enough room underneath for the drain to fit. It looks a little precarious, and I would like it to be the 4-5 inches lower, but it works for now.

The aquaponics ebb and flow growbed sitting on the aquarium light hood
The grow bed sitting on the aquarium light hood.
Aquarium filter filling the aquaponics ebb and flow growbed on top of the light hood
The canister filter has nearly filled the growbed. The water height is limited by the height of the stand pipe.
The bell siphon sitting on top of the stand pipe
The bell siphon sitting on top of the stand pipe. This is where the magic happens.
The bell siphon sitting on top of the stand pipe
Looking at the whole bell siphon drain.
Threaded drain gives me options in the future.
The threaded bottom allows me to potentially change how I drain this grow bed if I wanted to.


The growbed is continuously filled, and intermittently dumps into the aquarium below.

The drain in the aquarium
The water from the grow bed returns back to the aquarium here. The grow bed is still filling in this photo.
Bell Siphon draining into the aquarium
Bell Siphon draining into the aquarium. See all the water flowing out?

I placed my plants around the grow bed and the few items that where required to stay on the tank stand – family photos. I think it looks pretty good in the house! I hope to grow lettuces and herbs such as basil in it. Things that we eat regularly and are best fresh.

Indoor aquaponics setup on top of a fish tank
I only have desk lights with CFL bulbs right now. I think it looks pretty good!
Living Room Aquaponics in an aquarium
The tank looks good with the aquaponics on top!
I am pretty sure I can’t feed everybody in the photos… yet…



You can visit to see this same siphon and growbed in use on an expanded system.

Internet Explorer

This is my 500th blog post.

I started blogging, thinking that it may just be a fad for me, but it looks like I may be a lifer. I think my writing has improved a fair amount over the years, from all this practice!

My situation has changed dramatically since I started. Basically an entirely different life then back in Janurary of 2006.

I am still using that same computer I started blogging with – it’s been ‘promoted’ into the living room reciently. I can now blog on the comfort of my own couch!

I have some ideas for where I want to take my blog. I started twittering, and want to integrate the tweets into the blog timeline somehow. The template may get a slight update as well.

The blog will be moving soon to a new host (same URL – webiste address, just on a different computer) which should help speed things up a bit.

Oh, if your wondering about the title tag, a friend twittered today that he found a page where the title tag was ‘Internet Explorer’. I wanted one too. So, here it is. Just a gag thing, for me. But, it’s my blog, so I will abuse it as I want to.

Site Usage

  • 36,646
  • Visits

  • 47,208
  • Pageviews

  • 1.29
  • Pages/Visit

  • 86.03%
  • Bounce Rate

  • 00:00:51
  • Avg. Time on Site

  • 82.67%
  • % New Visits

I currently average about 100 people to my blog a day. My best day, I had over 1000 visitors!

You can see here my most popular pages.

Fifteen percent of people view my homepage. That means 85% of people aren’t interested in what I have to say now, just what I said at some point in the distant past. How is that for a boost to the ego… “Shush, I don’t care what you think right now…”

Oh well, I just keep talking to myself on my blog.

Aqurium Disaster

We woke up Saterday morning to this. Yep, a half empty 75 gallon fish tank.
The culprit is somehow my new Overflow Box. It didn’t seem to leak. The only thing I can think of is that one of the the drain tubes (looped back on itself here to test for leaks) was in a bad spot and caused water to drain out of the tank as opposed to into the tank.
Here I have looped the drain tube onto itself to test for leaks. I filled the overflow box up. Note the water in the box vs the green tank.
Here you can see that the water drained out of the overlow into the tank. So there IS a leak, but it’s on the tank side. Not a big deal, really. There is a joint on the tank side I can’t seem to be able to seal up.

I just can’t figure any better then the tubes weren’t long enough and moved in the middle of the night so water drained out the side of the tank.
I am going to cut longer drain tubes and zip-tie them into the inside of the tank.

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The more I clean, the messier it gets!

It seems like the more I clean my apartment, the worse it gets. I worked hard last week to get the living room and my bedroom cleared out. I also had the spare bedroom organized enough you could walk between the boxes to get to the fish tank.

Yesterday and today changed all that. Yesterday I dug out all computer gear and the desk and set that all up where it will go. I have yet to plug in a cable – they are in a few differnet boxes that I had to dig out tonight, but that ‘area’ is set up.

Tonight I moved all the boxes around so I could put my Electronics Hutch along the back wall where it will reside. That invloved filling the living room and my bedroom back up. I tried to move just boxes that will ultimatly get unloaded into the respective rooms, but a few extra ended up in each room.

I got the hutch moved, and unloaded off the carts. I have a really cool idea for building bookshelves around the hutch that will match it. But when I look at the rest of the room, I am not sure if I could utilize the space better or not.

I also put my 110 gallon fish tank in its final resting spot. It’s just setting on some sawhorses for now, but I really like it in that spot. I think I will set the big tank up as a Paludarium. I have a basement under me again, and so I can’t really set it up as a fish tank without risk of it falling through the floor. I am thinking of doing a waterfall that extends up and out the top of the tank, and having the plants ‘grow’ beyond the tank to take some of the squareness of the tank away.
We shall see what it turns out like. I need a stand first.

I am really in need of a couch. And a TV. I was looking around, and those new 32 inch LCDs would work out really nice. My entertainment center is occupied with the TV fish tank, but I left enough room to the right to hang a flat TV on the wall. That would work out to be directly in front of the couch that I don’t own. The couch I want would be a sleeper sofa, so friends & family have a place to sleep without listening to the computers all night long.

Oh well, one of these days…

DIY Homemade Custom 110 gallon Aquarium Stand Plans

I brought my 110 gallon fish tank to FL from storage in WI. This post is going to be as large as my tank!

I have big plans for my big aquarium. I have a pass-thru from the kitchen to the living room. I am going to build a stand that is tall enough to put the tank so it fills the ‘window’ in the pass-thru so I can watch my tank from the kitchen. This tank stand will be custom built for this specific space, but I will also take into consideration the need to move. It will be against a wall, or possibly BE a wall in the future.

This 1 tank stand will actually house 5 or 6 different tanks. It will also house as much extra water as I can put into it as part of a sump filter. I am also going to have some built in planters that will utilize water from the tank to water the plants – probably straight up hydroponics. I doubt I will use it for foodstuffs, but it would be fun to experiment.

Download Google Sketchup File

Tank 1 will be the 110 gallon tank. This will be the display tank. Decked out. Live plants. Under-gravel heating coils. LOTS of light. CO2 injection. Basically, a thing of beauty. I will have lots of little fish – the largest fish I will have in it will be a breading pair of Angel fish.

Tank 2 will be a 55 gallon tank. This will be the only tank I will need to purchase. This will be housed in the cabinet. It will also be a planted tank. No under-gravel heating. It will be a plant rearing tank. It will only have bottom feeder type fish in it and few at that. It’s main purpose is to run (lit up) at night to maintain CO2 and oxygen levels in the system. It would actually be considered to be part of the ‘sump’ filter.

Tank 3 and 4 will be 10 gallon tanks. These will also be planted tanks. One will be hooked into the main tank water supply; the other will be independent, but able to accept water from the main tank. The one piped into the main system will be my fish rearing tank. I can keep delicate fish in this tank or use it for rearing fry. The other tank, which will posses it’s own filter system, will be my sick tank. I will probably be able to attach/detach it from the water system. I may get a UV sterilizer for it to keep it as a sick tank, but keep the main water system hooked up to it on low flow, primarily utilizing it’s own filtering. Not sure yet on that part. Gotta research that idea. These two tanks would be in each end of the stand. They will probably both be set up to slide out on drawer hinges. Make it easier to access the tanks as there will be limited room above the tanks.

Tanks 5 and 6 will be my 4 foot by 4 inch by 4 inch nano tanks. By coupling them to my big fish tank, I don’t need to worry about all the little problems that come from a very small water volume tank. One will be incorporated into the fish tank stand on the ‘front’ underneath the main tank. The other will sit in the passthrough. These will be both set up as stream tanks with a decent amount of water ‘current’ running though them. With 2 of them, I may set them up differently. The one in the stand will probably be planted, as I can hide a light in the stand, and the one on the pass-thru will probably be just piled rocks.

The main filtering will be done by a type of filter called a wet/dry filter or sump. These sump filters look to be sized about 20-40 percent of the tank volume. I will see if I can push mine to be at least 50%. Each ‘stage’ of my sump might actually end up being separate containers nippled together with PVC pipe. I will probably end up using garbage cans due to their tall size and square form factor. That and they are cheap! The first section will hold bioballs. This is the one that the 110 gallon tank will flush into. I will probably have this one taller then the rest to support an extra column height of the bioballs to splash the water and air around in. This will probably flow into a second one, into a third, into a fourth, etc. The final stage of this sump filter will be the 55 gallon fish tank. I will pump water out of this 55 gallon tank into the rest of the tanks. And the water will gravity & siphon feed back into this tank through the rest of the sump filter. The water level in the 55 gallon tank will be the only water level that will fluctuate. I will probably position the pump pickup 1/3 to 1/2 half the way up this tank so I have room for 25-30 gallons of evaporation loss.

All the tanks will be filtered using a internal/external weir or sump overflow box that leads to the central sump filter. These are boxes that hang on both the inside and outside of the tank. They operate by creating a siphon from the inside to the outside box. As you drain water out of the outside box, the water flows out of the tank. These will be set up so that if the power were to go out, they would not siphon all of the water out of the tank. I will accomplish this by having the pickup tube either be a stand-pipe in the outside box or have a 2 chamber, outside box with the siphon leading into one part of the box and the water flows over an internal wall into the drain half. If the tank were to stop receiving water from the pump for whatever reason, the tanks will drain down to the top of the standoff or the inner wall height in the overflow box. By building the overflow boxes so they can handle several times the water flow of the water pump, I don’t need to worry about any clogged overflow boxes causing a tank to overflow.

I am thinking of building a storage tank automatic re-filler. I can’t plumb the tank to the water supply directly (as I live in an apartment). I like to ‘treat’ my water by aging it with an aerator. This aerator(s) will be the only aerator in the system – well maybe I might have one available for the rearing and sick tanks. The premise here is you let all the chlorine that the city may add to the water out-gas into the air. I also am not precipitating out any trace minerals out of the water that those treatment drops can do. This is important for raising live plants. I will use a toilet float (actually 2 in series) to allow water from the aging tank to flow into the 55 gallon tank to top it off. The aging tank will probably be a large, shallow tank/tub or two right below the main tank, above all the sump tanks and gear. This will have many baffles in it to force water to travel a long path to get from the entrance to the exit point. This will help prevent freshly added water to race it’s way to the 55 gallon tank and enter it un-aged. I will add a manual cut-off valve so if I allow the aging tank to drain completely, I can shut off the flow into the 55 gallon tank and fill the aging tank. This will force the water to age for 24 hours to out-gas and temperature acclimate. Then I can top off the 55 gallon tank, shut off the aging tank, age the water, turn the auto-fill valve on, and go back to my regular topping off routine. Kinda complex, I know, but call me paranoid. I just don’t like adding ‘fresh’ water to my tanks, either from the tap or from a pet store! I float my fish in a bucket of water that I siphon tank water into, and then net the fish into the main tank, so I don’t add any fish store water to my aquariums.

The main structure will be of treated lumber designed so that all load bearing surfaces have a direct path through ground. This basically means that there won’t be any screws or hanging brackets that bear weight. These are only to hold the thing together. I should be able to assemble the whole frame without any screws and it should be free standing. This baby will have a LOT of weight! 110+55+10+10+3.5+3.5 X 8.34 lbs/gal = about 1600 pounds of water, not including what is in the sumps, piping, etc. This is in addition to the roughly 275 of glass in the 110 gal tank, hundreds of pounds of rock at the bottom of the tanks, etc. As one website put it, it’s like standing your vehicle on it’s nose in your living room.

I will probably trim out the stand using oak, which, while not cheap, seems to be readily available here.

As for the lighting, I haven’t figured out exactly all the details of this. 3 watts of florescent per gallon is nearly 600 watts of lighting with the possibility of dimming lighting to simulate sunrise/sunset and blue/red/black lights for night viewing. The one thing I thought of, though, is that I am not going to want to pay the electric bill for this thing! I may end up seeing if I can run the bulk of it off of solar panels. The bulk of the lighting is during the day and into the evening, so I think this may work out. I am also thinking of running all the water pumps at 12v and running these off of solar charged batteries as well. I will probably run the two separately, or if combined, allow the lighting to drag the battery down through an inverter only so far before switching over to 110v from the power grid. Another benefit to this is that WHEN the power goes out (it does it a lot down here in Florida), my pumps have an inherent backup system. Additionally, if the batteries are running low and 110v is available, I will at least partially charge them back up. Just in-case it’s been rainy all week, etc. I could also top the batteries off before a hurricane, so I can run just the pumps for an extended period of time.

I plan to have this tank ‘wired’ to the internet. I will be making leak detectors, water level sensors, lighting sensors, temperature sensors etc. and wiring them into a rabbitcore Ethernet enabled micro-controller. This will allow me to ‘page’ my cell phone via its email address if there are problems with the tank. While the tank should be able to find it’s own safe ‘stasis’ level, maybe one of my cat’s could get inside and really bugger things up! I am also probably going to wire in at least one webcam into the tank. I may include a pan/tilt inside the cabinet as well. The feeders will all be the automatic feeders I am building. The lighting will be controlled as well, so if I want to watch a movie, I can turn the lights down low on the tank.

I am thinking of building the tank stand about 4-6 inches larger then the tank on the ‘front’ 3 sides and build into it a hydroponics setup around the base of the tank. The tank will feed the plants water and food and I can utilize the stray light coming off of the tank for the plants. I probably won’t use this for edible plants, but at the very least, I can have some nice low flowers like violets that will be 0 work plants.

I really like the looks of my CO2 reactor. I am thinking I may incorporate two of them into the outside corners of the stand and backlight them with black light or something. If I did that, I would probably bubble them up from the bottom or somehow make a separate bubble counter.

I have always wanted to incorporate a small bookcase into this stand. It is starting to get a little full, so I may do a book display type concept instead. I can display a few fish/aquarium related books on it. Maybe something low so the little kids have something to read – and identification books. Oh, maybe a photo album type book with photos of all my fish and a little about each type. That might be cool.

Anyway… what are your thoughts?