Backyard Aquaponics
A place to discuss aquaponics

Thinkm he's still gunna puke... just cos he didn't think of it...

Looks great mate..... as Steve said hook up the AP to the trays and give, it a go.

Eventually I'm looking to do the same kind of thing although with more traditional nft gully, mainly cos I've got plenty.

Only problem I'm aware of and perceive is the possible clogging of your holes if you utilise the AP water because it contains fish waste solids and particles from undigested fish food.

Others that have utilised hydro type equipment have found that it's beneficial to incorporate some kind of "solids" filter/trap before pumping to the nft.

i.e a half blue drum (100ltr) filled with gravel/shells/sand/cocopeat etc.

This traps most of the solids and acts as another place for them "good" bacteria to breed and do their thing to convert and produce the nutrients for the plants and ultimately breaking down the solids.

"balding bearded duder"

You fit in perfectly......

hehehe

Just did a backtrack and double take.... sure he's not a lost relo EB....

Member of the family

And also the "stuff" clinging to the plant roots giving localise hig oxygen demand and sort of smothering them.

Greetings ...

I was hoping you guys/gals could hopefully point out some flaws in my thinking. This was the design of my next AP system, but I think I'm going to be moving soon as a result of a new job. That being said it doesn't make sense to stock it with fish just yet. Anyway...poke holes in the ideas...the thing i'm concerned about is the flood/drain time with the auto siphons and the number of bed's compared to the size of the stock tank.

Currently it's setup with 4 half barrels and a 300 gallon (1100'ish liters) stock tank. The pump is a 6xx gallon (2xxx liter) per hour pump. The auto-siphon drains a bed in ~ 5 minutes. We haven't really determined a flood time yet, since I'm away for 2 weeks...and the project was put on hold.

Will this size tank be able to handle ~ 100 tilapia? Will we need more GB's for more that amount of tilapia? Will we need less gb's for that amount of tilapia?

As always, I've attached a picture of the hydroponics tomato/pepper garden...since that's all i really have to show at this point

Hi Bochener!

You will definitely want more gravel volume, if not right away then definitely as the fish mature. I have as much gravel for 60 tilapia and its not enough to cope with the solids and to grow enough plant mass to keep up with the nitrates. The general rule of thumb is 2 gallons of water per pound of fish, and twice as much gravel volume as fish water volume. Your 300 gallon tank could handle 150 lbs of fish at max density, but you might not want to push the envelope that closely. Tilapia are ready at like 1 1/2 to 2 1/2 pounds (I think?), so you would fit less than 75 fish at 2 pounds.

Is your pump set to be continuous, or is it on a timer until the beds have started siphoning? 5 minutes would be fine if each bed is running on its own timing (meaning continuous pump with many bed siphons) - with enough beds running on siphons some will always be close to draining while others are filling.

I think you could start eating tilapia at 1 pound (about .45 kg, but I don't have my calculator on hand). That would dress out to about a half a pound per fish.

Yes, in theory, 300gal of water could support 150 pounds of fish, at max capacity and max filtration, and with an experienced fishkeeper. However, If I read it right, there is only 100gal of filtration (4 half barrels). So my math says you could support (100/4) 25 pounds of fish. So I would stock only 25 tilapia, and start eating at one pound in weight. That said, my system is similar in size, and I'm struggling at 10 pounds of fish. My system has 150gal of filtration, and another 150gal of fish tank. With about 10 pounds of fish in there now, I am having problems with nitrites again. I am debating re-making the autosiphons (again) to get higher flow rate, although I already turn over the water at 3x/hour. I am not able to feed as much as I think is needed for optimal growth, and I'd really like to get decent sized fish for a meal this summer.

Whoops. And with a 6xx gph pump, you'll probably only be able to move 4xx gph, allowing for head and turns in the plumbing. So you'll be turning over your tank volume at less than 1.5 x/hour. I revise my Recommended Tilapia Allowance (RTA) to 'not more than 20'.

Unless you wash more gravel, of course.

Thanks, I'm currently in Bushkill, PA...getting some silly Cisco certification...but can't stop thinking about the AP. On the topic of washing gravel...WOW that's a horrible task...but a necessary evil. I had planned on building another 2 or 3 barrel stands like that... but with the idea of moving it's all on hold. I'll keep these recommendations on fish stocking in mind, and consider a whopper of a pump in the future.

Yes, I read that as 6xxx instead of 6xx. That is about what I have with my two little pumps, which service the 100 gallons of beds OK. Plan to add a lot more gravel volume if you want to grow out that many fish. You fish tank is big enough to handle a lot but the gravel volume needs to go up a lot.

This is the same situation that JP and I are in as well, welcome to the club!

FWIW I didn't wash any gravel this time around... Lots of sand in the gravel but it was winter and frozen up so I just put it in. No problems so far (since Feb).

If you get closer to G'burg let me know and we'll hook up!

I'm southwest of Philly. Stop by and I'll give you a tour of the system. You're 3 hours away from me right now. To get from IN to Bushkill, did you fly into Philly or JFK or what?

I flew into Newark...rented a car...and then drove here.