Aquaponics Discussion

Wanted to start a topic for people wanting to discuss, ask questions about, or to get involved with the aquaponics system.

You can get a much more in-depth look at the design decisions, and considerations that were made for the system back in the old Aquaponics Build post from a while back -> Aquaponics Build

For some quick answers to some questions i was recently asked.

-the growbed is 12sqft, 4ft longx 3ft wide x 1ft deep
------ the volume of growbed media is the single largest limiting factor in how many fish the system can reasonably support.
-the media is hydroton expanded clay pebbles used as a neutral media to give the plants roots a structure to grow in, and allow the beneficial bacteria a place to grow.
-1ft deep is considered deep enough for most plants to secure themselves in and gives plenty of room for the beneficial bacteria to grow in.
-The system could handle many more plants than it currently has, there is a limit to how many it can handle, adding to many and they wont get enough nutrients to flourish. To few and the water wont filter effectively. This is determined by regular monitoring of the nitrite levels int he water.

-140 gallons
-currently has a 700gph pump to help circulate the water between the tank and the sump.
-----The actual flow rate is less than 700gph due to head height and hose restrictions.
-the fish is mozambique tilapia, they are considered an invasive species, and under no circumstances are they legally allowed to be removed from the building, without first “having their heads removed”. (as the store clerk i purchased them from instructed me)
-the system is intended to house 8 full grown adult tilapia.
-tilapia breed like rabbits so population control can be problematic

-the system does super well for leafy greens and hardy plants
-flowering plants tend to struggle due to a lack of iron in the fish feed
-vine plants do really well, however they can become nightmarish in how they over run the system.
-----In my old system i tried planting some English ivy, and it took to the system really well, and slowly took over the entry door for the facility and it was beautiful. However when i had removed the plant i found it had dozens of small sprouts spring up and for the next year i was constantly having to remove the sprouts.
-----if we wanted to do an ivy, i would recommend setting up a secondary/mini growbed for it to grow in so it doesnt infect the main growbed.

-This project is a community project. My goal is to use it to help others spring board their own similiar projects and experiment things.
-When i was first starting on the project the other team members were interested in making their own home made growlights and cultivating algea, but those projects never really took off like they had hoped.
-I live in San Antonio, its 3 hours of driving for me to go in and do the monthly maintence on the system. so having others that could help out or do small maintenace on the system would be very helpful.
-I want to encourage others to get invovled with the system, adding sensors, automating control, trying different plants, etc. my only real concern is in making sure if somebody does something to the system that im aware of it. Just wanted to know in advance when a new plant is added or something is harvested. (also so i can make sure things are ebing harvest properly so as to not kill off the plant)

If you have any questions, or concerns about the system please post them here. Like said i want this to be a community project, so i want to encourage others to get involved, try new things and to help keep this mini-ecosystem healthy.

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Thanks for the information. I think right now the biggest issue is the tank is 90°f. I’m not really sure how to solve this.
Edit: digital sensor says 84, analog says 90.

What prep needs to be done to do a water change?

I will look for people willing to take some of the fish. If nobody is I’m not opposed to mercy killing the large ones. They’re are way to many fish in this tank.

A water change shouldn’t be necessary, as the water gets cloudy its a sign that the pipes need to be cleaned, or the pumps needs to be repaired. the pump for the grow bed has been having trouble lately so it may be time to replace it. (the point of the system is to keep it self sustaining as much as possible, the system hasn’t needed a water change since i setup the system 1.5 years ago)

If a water change were to be performed the procedure would be.

  • turn off the pump
  • remove the overflow tube inside the fish tank
    -----wait for the water to flow into the sump till the 75 gallon mark.
    ---- once the sump has reached 75 gallons then re-install the overflow tube to stop it from flowing into the sump anymore.
  • setup a siphon tube to drain into the parking lot.
    -----(the outlet of the drain tube needs to be wrapped in cheese clothe to ensure no fish are able to some how escape into a nearby creek by some odd miracle)
  • now you can start to refill the system using water that has been piped through the inline declhorinator.
    ----I typically have the water added to the growbed to help aerate the water, and give it time to even out its temperature before it reaches the fish tank so it doesn’t cause any temperature shock.
    ----Austin uses chloromides to treat its water, chloromides will not offgas and will accumulate int he system NEVER ADD UNTREATED WATER!!!.
  • as the water is refilled you turn the pumps on and off periodicly. when the waterlevel in the sump is above 50 gallons you’ll turn it on, and off when its 25 gallons. youll repeat this until the water begins to flow out of the tank again.
    ----- the reason you do this is so the water being added has a chance to warm up over the tank heaters in the sump, and beneficial bacteria in the water has a chance to mix.
  • once the water level in the tank has reached the overflow and is now cycling between the tank and the sump, wait for the water level in the sump to reach 75 gallons, then turn off the water hose.

As for giving the fish away, that is not an option, they are considered an invasive species and you are required to get a permit in order to transport them. I had to sign the permit to have permission to transport them to the space, in the permit i had to agree that they would not leave the destination.

For the over heating, its been a concern for a while, thats why i have the garbage bags over the tank and the sump to try and keep the sun light from heating it up.

The Fish are able to handle temps up to 95F, but ideally it would be below 80F. Here is a tracking table where i list the ideal/allowable ranged for different metrics in the system. ->

It is possible one of the tank heaters has broken and is stuck on. I removed one that was stuck on a couple months ago, so it may have happened to another heater.

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Where are the heaters bc its keeps going up.

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Found it, it was on

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Thanks hopefully that’ll help take some of the heat off. None of the heaters should be on with that tank that warm.

There are multiple heaters, I have them set at different temperatures so as it gets colder more of them would turn in. It’s more important in the winter months. And keeps it from suddenly turning on 2kW of heat all at once for a minor chill.

You’ll want to unplug that heater and let it sit in the water till its cooled off. If you take it out of the water, even with it unplugged can cause it to over heat.

I’ll go ahead and order a new pump. For the growbed to try and get the water to clear up.

Also anytime your working on the system wash your hands without any soap. The soap can be harmful to the fish and bacteria so just use some warm water and light scrubbing.

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I found two measurements for the number/size of fish. One is biased off the volume of the wet grow media (25L = 500G of fish) and the other is a standard fish tank rule of thumb (13-25mm per US gallon). I will count and measure the fish some time this week.

@Tookys when do you plan to come in next? I would be willing to learn the ropes and help when I naturally come in but I can not commit to anything set in stone. My usage of the HS fluctuates. Some weeks I am there 3 days some months I go without showing up at all.

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I try to be there 10 am the first saturday of each month. Or we can pick some saturday to meet.

The week of Thanksgiving I could also come by during the week.

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As for giving the fish away, that is not an option, they are considered an invasive species and you are required to get a permit in order to transport them. I had to sign the permit to have permission to transport them to the space, in the permit i had to agree that they would not leave the destination.

So… fish fry? :slight_smile:

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I’d be up for one lol.

I’ve had to use special fish food, standard fish food isn’t safe for fish intended to be eaten.

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Would it help to put more plants in? Aloe is a pretty slow grower so I imagine the bulk of filtering is up to the basil and ivy. I don’t mind grabbing a few leafy plants to add in.

I’m also curious about the growths on the fish. Do we know what that is?

I looked into the growths before and best I could find was that it was a bacterial infection. No real way to treat it, but I may be wrong.

We definitely need more plants added.

If you have ideas for what to add let me know. Touch base with me before planting them though so we are both on the same page

I was thinking that lacinto kale, collards, or mustard greens would be good. They all like heat, are fast growers, survive a hardy cutting back, and live for a long time. A friend of mind has an 8 year old, 6 ft tall kale that is super cool looking. She really encouraged the height growth so they wouldn’t necessarily get that big quickly.

I also just noticed the big aloe in the back today. It’s huge!

Kale and collard would both do well.

The Aloe was first planted even before the fish were added when the system was first cycling. it was only a tiny 6" tall home depot aloe when it started. i plan to keep that there indefinitely to see how big it can get.

I like to try and grow things from seeds where possible. would you be able to get some seeds? i can walk you through the prep work for planting. I currently have the growbed in a 4x3 grid for spacing out the plants.

We’ll need to plan what plants we would like to plant where.

Yes I can pick up some seeds. I’ll message you when I have them.

It also occurred to me that raphidophora tetrasperma would enjoy the growing conditions and is a beautiful vine plant. We could do one near the front of the bed and have someone lasercut a pretty trellis to encourage vining in a shape we choose. I have one plant and could attempt to propagate a cutting for future use if there’s interest.

I’m semi-hesitant to add a vine plant to the main growbed after my last one was over run by english ivy.

We could try making a side growbed by the fish tank, where we could add the vines.

Hi James! I have seeds for the aquaponics bed. I also noticed that the grow lights have been off the last three times I’ve come to the space, all at different times during the day.

Cool, I’ll setup a meeting to discuss seed planting and etc soon.

Sorry, schools been kicking my butt lately so I’ve been a bit quiet.

The led lights are only on from 7pm to 1 am. So unless your there late at night you won’t see them.

@Tookys I noticed that there is a lot of algae in the fish tank and the lights for the tank look like they are on for a significant portion of the day. In order to keep the algae down that do you think about cutting down on the time the tank gets light? Is there a timer on those lights that can be adjusted?

On a side note, I have researched and done basic hydroponics with a similar setup before and currently have a few freshwater planted fish tanks at home so let me know if you need some help with anything.

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