Backyard Aquaponics
A place to discuss aquaponics

Quick question: I took the gb apart because im moving it to a spot that gets more sun....When i set it up last time i forgot to drill the 1/4in hole in the drain pipe. Im pretty sure its for if you have a timer, not constant flood but just wanna make sure. Do i need it in my table? would it be bad if i drilled it with a constant flood table? thanks

No, you don't need or want a hole in the base of the pipe when doing Constant Flood. Allowing water to drain would require resizing the sump every time you added a grow bed because you'd have to plan the sump size to hold all the water if there was a power outage. Not having to do this is one of the advantages of CF, it's easier to expand the system.

Nice start Lou. Just FYI if you are looking for Blue Tilapia here is a great place to start reading about Tilapia in general but they also sell Blue Tilapia. https://lakewaytilapia.com/

I actually just bought 10 Blue Tilapia from Tampa Aquaculture for about $21 (including shipping from Florida to Michigan..), they ended up shipping me 13 of them in case some don't make it in shipping, which took 2-3 days to go that distance, but all 13 of them survived... it took them about a week to get used to me coming in to see them and now they go crazy when they see me knowing I'm going to feed them (I also have an automatic feeder set up for them too but always toss them some extra when I go to check on them). https://tampaaquaculture.com/collection ... 3324720001

The Lakeway Tilapia website is very helpful for learning about Tilapia... and they claim that you do not need to cycle Tilapia systems because they claim ammonia is non-toxic to Tilapia below 8.0 pH, (so they recommend keeping water at 7.0 or lower) then they claim that nitrite IS toxic to Tilapia, but the only effect it has on them is to reduce the amount of oxygen their blood can absorb but isn't typically an issue with the levels you'll see through cycling with Tilapia as long as they aren't too stressed and over-exerting themselves it isn't an issue.

I'm not sure if your question about the plumbing of the water pump line was answered -- I would think you should be able to move the plumbing under the growbed and still keep the same number of 90's as what you had originally so it should not affect the system... with that said a plumber once told me that a good rule of thumb is that every 90 degree fitting in a system is basically like adding an additional 10ft of plumbing... so the less 90's the more efficient it will be, and if you can change 90's out to 45's would be better too.

Awesome, thank you for those links. I'll be ordering my fish from Tampa Aquaculture. Just want to make sure i have the correct feed and such....While they are fingerlings, i was thinking of using Purina AquaMax Fingerling Starter 300, and when they get bigger I was planning on using Purina Mills Aquamax 4000 Extruded. How are those feeds? does that sound ok? Also I am probably just over and over thinking it but, with the water that im going to put my fingerlings in...does it have to have anything in it prior to me putting them in there? will just regular ole water from the hose be ok? just keep the water under 8 pH and everythign will be okay? lol...I have a fresh water test kit on its way as well. Thanks again guys

Actually the 10 fish im going to be getting are 1.5-2 inches, so I was thinking of using Purina AquaMax Fry Starter 200...how does that sound? Also confused about when they reproduce and you have different sizes of fish, what do you feed them? give them fingerling and bigger food for the bigger fish or just once feed? Thanks

Purina has a food that is a mixture of sizes for ponds with different size fish, but personally my plan is to take any fry out from the adults so I can control their tank easier and keep track of them better. I bought a 50lbs bag of aquamax 400 for my trout so that is what I'm using for my tilapia right now too, they were too big of pellets for the tilapia at first so I am using a small bowl and the back side of a screw driver as a mortar and pestle to crush the pellets, after a couple of weeks they are big enough to eat the 400, but I'm still crushing them for a little while longer. Eventually I will have a little of everything. I am going to pick up some 500 for the trout soon, but I think from what I've read the tilapia will be good with the 4000 for long term feed. I ended up repackaging the 50 lbs of feed in to smaller bags and vacuum sealed them to make it last longer because it will take years to use it all if I use different sizes.

As for setting up the tank and just filling it and keeping the pH below 8, that's what Lakeway tilapia claims, which they seem to be pretty informative and trying to fix some misconceptions about tilapia, so I think it's worth trying it. If you fill it from tap water you should probably add some conditioner to it (if you are on city water, if you are on well water it is a lower risk of having chlorine in the water unless you know you've bleached/chlorine your well, but you could fill the tank and have it run for a bit before the fish get there would give it time to offgas the chlorine too)

"Ok I guess ill have to be patient...darn...." Yup I am right there with you.

Another reason to run well water before is to degas any high concentrations of CO2 in the water.

Ok so once the fish are in my tank, im feeding them regularly, do i run the pump that pushes water through the grow bed 24/7, at all? or do they just sit in their tanks for awhile? I was planning on letting the water sit out for a bit before putting them in there but i also have some dechlor im going to put in there. I got my test kit in the mail the other day so now im just wondering after testing how can i adjust things....ph? nitrates? nitrites? ammonia? what do people use to adjust all these?......whatever else i might have to adjust.

If the water just has chlorine in it then don't add the dechlor, it will gas off on it's own over about 24 hours. If it's chloramine that's a different story - you should check.

How big are these fish going to be?

You adjust ammonia and nitrites by letting the bacterial biofilter process them to nitrates (ideally without letting them get high enough to harm your fish - once your system is running well nitrites should be zero and ammonia should be a trace at most). The plants adjust the nitrates by using them as fertiliser; if levels get really high you can do water changes to bring them down.

Adjusting pH depends on what your supply water is like and how much it drops naturally. As the bacteria process ammonia into nitrates, that drops the pH; if your topup water has a medium-high pH or is slightly hard, it might keep the pH within the ideal range without you needing to do anything else. If your topup water has a very high pH or is very hard, you'll probably need to treat it (carefully!) with acid before adding it to the system to bring it down. If you're using rainwater you'll probably need to add carbonates in some form to your system to bring the pH up. Don't worry too much about it until you see what your system does naturally, and if you do end up needing to adjust things, do it gently and gradually!

Once your fish are in the system you need to be running the pump, 'cause that's what's going to filter the water for them and supply a lot of the necessary aeration (all of it if you don't have an air pump too). Run it the way you're planning to run it normally.

Ok, so lets say my top up water isnt at a ph i like, can i then add a ph up or down to that water? or is something like that harmful to the fish?

Ive read that tilipia are ok in water over 50 degrees but not under. I have a 150W heater that i just drop in...will that be enough to heat all the water if it gets under 50?

The fish Im getting are 1.5-2in fingerlings but Im hoping they get about 11 inches before harvesting them.

You can adjust the pH of the water.

Usually Hydrochloric acid (HCl aka Muriatic Acid) is a good choice for adjusting the pH down but use all necessary precautions and keep stored away from kids. Typically after the system gets going you won't need to add acid because nitrification will do this for you but in Florida you might have high carbonate hardness that keeps the pH high, every system is a bit different

To adjust the pH up there are several options including hydroxides (like CaOH or KOH), bicarbonates (like potassium bicarbonate or sodium bicarbonate) and carbonates (like calcium carbonate). I listed these from strongest to weakest.

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On the heater, I don't know. It will depend on how cold it gets there and the volume of water you're trying to heat. Most tilapia can go down into the mid 50's but if they are there for long periods their health will suffer and they'll be stressed out. If you're growing Blue Tilapia they are more durable.

On the heater issue, reading on the Lakeway tilapia website I linked they say that blue tilapia can handle the lower temps, they say 47 degrees minimum but they still prefer warmer water, normal temp range they say is 60-86F... a lot will depend on how quickly you want the fish to grow. The warmer the water the more they will eat and the faster they will grow. I think Lakeway recommended 80F temps for the quickest growing of blue tilapia, and I think it's something like the first 240 days of the tilapia's life are the growth days where they have the highest feed conversion rate, so they say you can get them to 1lb in 240 days, then after that they start costing more to feed with less gain so that is when they recommend harvesting them. To maximize growth in that 240 days you need the warmer water temps.

They say the minimum breeding temp is 68 degrees, but ideally 80.

So how does that compare to what the water temp will be with a 150W heater? Well a lot of it will depend on your air temps how low they get to get an idea what the coldest the water will get without a heater. Just for comparison, my tilapia are currently in a 20 gallon aquarium in the lower level of my house. I keep my house thermostat set at 68-70F depending on the time of day, but the lower level of my house stays a bit cooler than that, I don't know the exact temp but lets say probably 5 degrees colder so 63-65F. I believe it is a 150W heater I am running in the aquarium and I have it cranked all the way up as high as it goes and then I use my controller to turn it on and off instead of the internal sensors of the heater. I set my controller to turn the heater on any time the water temp is below 76F (I was gradually increasing it to try and hit 80F) but with that heater it's barely capable of raising my 20 gallons of water to 76F, it's hovering between 72-76F. I will probably toss a larger heater in so I can keep increasing the temp until I get them to breeding size then I'll gradually reduce the temp back to the 68F minimum breeding temp once they have reached the appropriate size to start breeding (at which point they will move in to a much larger tank, so I will drop the temp in order to save some money on heating the larger tank once the fish are breeding size. The fish that don't get saved for breeding will eventually get moved out to the greenhouse and live in whatever water temp the greenhouse sets it at, but this will be summer time by the time I move them out because I have trout out there for the winter)