Backyard Aquaponics
A place to discuss aquaponics

Hello, I am a middle school technology education teacher in NY. Last year I started a small hydroponics lab in my class and have expanded it for this year. I would like to introduce a small aquaponics setup as well.
There was a fish tank in the basement I found that I can use that is probably about a 20-25 gallon tank. I want to use this to build my system out of. I have extra water pump and air pumps to use as well. My plan is to use a storage tote as a grow bed with a pvc bell syphon.

Now my questions:

I plan to use goldfish right now to learn since it will be a fairly small system and am more concerned about creating another learning experience than growing fish and they are cheap. How many gold should I use in a system this size?

Are there any reliable yet cheap auto feeders I could use as it is in the school and I will not be there on weekends, holidays, etc.?

I have an electronic PH meter and a PPM nutrient meter. What else would I need to monitor in an aquaponics system that I would need other meters for?


If your interested in seeing what I have setup with hydroponics already you can look here. https://sites.google.com/a/elwood.k12.n ... ydroponics


Thanks for any help
-Matt

Hi Matt,
I have designed a small/indoor system for my sons goldfish that doubles as my research lab:)
I found the smaller a system the higher the temperature swings form day/night heating/aircon and so on...
This will limit your choice of species without a chiller and heater
How many depends a lot on your gb size, media, flow rate, plant species and density, extra filter size and type.
Nutrient ppm test and supplement is important if you use cheap goldfish feed.
I have no experience with auto feeder but am sure your local aquarium supplier can help.
Last a tip: enclose the fishtank to keep over enthusiastic helpers from over feeding or food colouring pranksters out
Ben

Hi Matt!

There are really cheap auto-feeders to order from dealextreme, dx.com
http://dx.com/p/automatic-fish-feeder-with-digital-timer-2-aa-49494
Free shipping all over the world...

What you need to get is a "pond water test kit" where you can measure NH3, NO2 and NO3 along with pH. Usually if you buy a kit there are some other usefull test's included as well like KH.

The PPM nutrient meter you have only measure dissolved salt's in the water, NO3.

I'm am not an expert on fish, but I would advice just getting a few goldfish, maybe 4-5. They grow fast if you feed them, and with a smaller number the risk of them dying from nitrite poisoning or other causes decrease.

Fish can survive for ages without feed, so don't worry about the complexity of auto feeders. As a school project you are not trying to grow the fish quickly, rather supply nutirents for some vegies.

Keep in mind you want to follow the KISS philosophy.

Welcome Matt!

Kudos to you for demonstrating AP to your students, there are a lot of possibilities for learning with an AP system. I've been wanting to offer to do the same for my son's science class in middle school as well.

I would use constant flood instead of a siphon, less complicated just as good without the noise.

I agree the 4-5 goldfish would be good for a 20-25 gallon tank. You'll be surprised how much you can grow with just a few goldfish.

The usual API ammonia, nitrite, pH kit will be sufficient to keep up with the system's water parameters. http://www.amazon.com/API-Freshwater-Ma ... B000255NCI

Agreed with noice. Splashing syphon drain in the classroom would increase toilet runs:)
What I did with my indoor aquarium setup was extending the return pipe from bell syphon all way down to the bottom of the tank. Drilled a hole well above the high water mark to allow for venting when the syphon stops. That hole works as a Venturi when draining and the water pressure sucks great amounts of air right to the bottom. Works great and very silent.

Thank you for all the replies.




Thanks. If you want to take a drive up to Long Island to set something up here let me know! hah

What do you mean by constant flood? More like a drip system or like a timed flood and drain?

I will look into the water test kits and plan of 4 gold fish to start.



quote="dr bee"]Fish can survive for ages without feed, so don't worry about the complexity of auto feeders. As a school project you are not trying to grow the fish quickly, rather supply nutirents for some vegies.

Keep in mind you want to follow the KISS philosophy.[/quote]


So you don't think it will be an issue over the weekend not feeding the fish?



Another question. For inside the fish tank I assume I need some aquarium gravel. Does it matter what is used for that, will some types of stones throw off the balance of the system? Are their any live underwater plants that would be good to add to the system or is it best to go with artificial?





Is there any specific goldfish feed that works best to keep nutrient levels balanced?

I do need to try to find (or make) a cover for the fish tank as I currently do not have one! That is on the list already. I am not too worried about the temperature variations as it will be with the hydroponics is a fairly secluded area which so far seems to stay a consistent temperature. We will see once the outside temperature continues to drop lower though. You can see below the area with the light peaking out that all the growing wonders take place in.



The

From what I learned and read you don't need gravel, or plants in your fish tank. Or a castle shaped like a pirate skull... It's something aquarium shops tell you that you must have so they can sell you more stuff.
Those things are for the humans, not the fish.

Gravel just creates an environment for anaerobic bacteria to grow and contaminate your aquarium. To clean it you need to buy a gravel vacuum-cleaner, at the aquarium store...

As for the plants I think the gold fish will just eat them all. And plastic plants are for the humans... They would rather have some shelter. Like keeping a part of the aquarium in darkness with an opaque cover.
The aquarium lights is also for the humans, and the algae.

Goldfish can go weeks without feeding. Have just read that, haven't starved fish for that long to test. But 2-3 days without feeding is no a problem at all.

I would buy a good koi pond feed. Fish food made for aquarium fish is usually made nutrient poor so the fish don't get to big.

Yep you want a clean bottom in the aquarium so the solids get to the bed.

+1 weekend not necessary to feed.

About temperature goldfish can handle anything you've got as long as the temp changes are slow. I had one that lived under the ice in a little outdoor pond and that one also lived in a small aquarium on the deck that reached 100 degrees too.

Constant flood meaning the water level stays the same all the time instead of flooding and draining using a timer or siphon. There is a comparison that Joel did with different schemes and you can't really tell the difference between flood and drain and constant flood.

BTW I have two koi and two goldfish outside right now and as the temperature gets cold I don't feed them but a little bit every few days. If they stay out there I will stop feeding them entirely.

Any goldfish food will be OK, you might want to look into getting Maxicrop with iron but only if the plants starts looking like they are missing iron.

So ideally nothing inside the fish tank but the fish, water pump and air pump? That seems like a boring life for the fish.

If the water is constantly at the same level in the grow bed it wouldn't create a lack of oxygen in the water in the grow bed?


So for a start I am going to get 4 goldfish for the fish tank with a plastic storage container as a grow bed filled with hydroton. Pump the water into the container and add a fitting to the side a couple inches up to drain back to the fish tank. Air pump in the fish tank. Then feed the fish and get a pond test kit. Are proper water test levels listed somewhere? What would be best to start with growing in this system? In my hydroponics systems I have a variety of lettuce, spinach, basil, swiss chard, kale, peppers, tomatoes, broccoli, carrots, squash, and parsley (I think thats it).

I have been reading through a lot of other information but it seems most is more advanced and for larger systems than what I am looking for right now. Although I am sure I will get to that point.

Thanks
-Matt

I like to put a few pieces of PVC for the goldfish. Gives them a place to hide. One of DH's early test projects had the water from the drain dropping from a height to help aerate the water. Unfortunately it gave the poor goldfish concussions. I put the PVC to give them a place to avoid the drain cycle until he got it adjusted. Now, if it is a small system with small fish I just put the pipe pieces in out of habit. Both small goldfish and small tilapia seem to like them and it doesn't hurt anything and after the build you will gave small pieces of PVC left over. Might as well use them IMHO which is worth nothing

Several months later, finally got everything else figured out enough to find time to get the aquaponics system up and going. Heres a picture below. The 5 gallon bucket is a seperate hydroponic system just places there to share the light source. Added a cover for the fish tank and two goldfish for now to get the system going and plan on adding one or two more ones everything cycles out. Ended up doing a bell syphon to try it out and it works well so I am gonna leave it that way. Will post more detailed pictures if I the snow ever stops and we get back to school.

When I put the goldfish in the water was at a level of .25 ammonia. Two days later after adding two goldfish the levels jumped up to beyond the color of the 8 on the test kit. What would cause the ammonia levels to jump that high from just two goldfish that were only fed once in the tank?

Shouldn't do that, did you try measuring a couple times? Are you sure no one added anything to the system?

If your top up water had chloramines in it for treatment instead of just chlorine then that can turn into ammonia.

Are you using the drip tests or strips? The strip tests are unreliable.

I did check it a couple times. It is the drop tests. Color continually gets darker and darker.

I had the water in the tank with the air pump for several days before I added fish to it.

I have the tank covered and didn't notice any students put anything in it. I don't know what they would have or want to add to it that wouldn't be noticeable in anyway but ammonia levels.