Backyard Aquaponics
A place to discuss aquaponics

I have 20 tilapia and 19 BlueGill varying in size from 3-7 inches. I feed about 2 tablespoons (I don't measure - just a small handfull) when ever I feel like it. I probably have been feeding them 5 or 6 times a day. I found any more then a small handful and they do not consume it right away. After a couple hours they get hungry again and will feed so I go ahead and feed them. I would like these to grow out before the temps start to drop in October. The plants have been going nuts with the nutrient rich water too! I stopped testing as soon as the amonia dropped enough to add fish. On the otherhand, I routinely only feed the fish in my reef tank once every couple days as I do not like doing water changes and I don't care for them to get any bigger. But I am new to this so it could all come crashing down on me - maybe I should do some water tests...

OOOOO K

I know I'm probably gonna get flamed here, and it's kinda against what every one is thinking and I am only 1AP month old, BUT :::

It has been average temps today in the mid 70's and when I went out this AM it looked OK.. the plants seemed fairly happy, but a couple were a little wilty, esp the large tomatoes and a couple of the peppers..

I went out this PM at 1145 and everything looked great ! The toms perked up, the peppers looked happy and all was well !

The trouble is the system doesnt flood and drain between 10 and 1, so the plants had no water (and no sunlight) for almost 2 hours..

I just went out and looked at them, and they look alot heathier than they do during the day..

My fill is about 1/4 of the tank, it heads into the GB and drains over 45 mins.. trouble is my timer only has 20 cycles, so there are a couple of hours that there is no cycle..

What do you think ??

Joey

I'm assuming you mean you don't pump between 10:00PM & 01:00AM... that's fine...

Indeed many of us deliberately take pump cycles out through the night time... especially during winter... in order to maintain heat in the tank overnight...

You plants may have been wilting in the heat, due to transpiration... obviously this doesn't occur during the night..

Joey,

I cycle mine one the hour from 7 a.m. to 8 p.m. and then at 11 p.m. and 3 a.m. Earlier when it was really cool at night I shut the pump off altogether from 7 p.m. to 8 or 9 a.m. Air only to FT during this time. Plants don't mind.

Guessing as the tank temps start hovering in the mid-80s and the days get hotter, I'll extend the time between day cycles and run more cycles at night to cool the water in the system. A bit of a dance, but not too complex with these little timers. Just have to be sure the water is completely draining between cycles...

Could be a combination of other factors that gave you the impression.. Are the plants shaded or in full sun the whole day. What is your water temp and if there is too much time between day cycles, is the surface of the gravel getting too warm?

May be other things to ponder/think through...

CB

A quick update,
I'd moved 5 tilapia to a seperate tank to test feeding them spent brewers grains.. then I started reading about duckweed.. I moved the 5 Tilapia that I was testing on spent brewer's grain from the 60 gallon fishtank into the house, and abandoned the spent grain idea, having found a FAR more sustainable solution.. Duckweed ! It also provides complete nutrition for Tilapia I've heard ! So I've started two small 1'x1' patches in the 60 gallon aqarium, within a couple of weeks I should be able to remove a couple of handfuls a day to feed the fish, and it will regenerate by the next day !! It will hopefully "close the loop" of the system, making it at least partially self sufficient ! The five Tilapia that I brought inside are doing well and I am hoping that they will breed, I'm cranking up Marvin Gaye as we speak>>

The duckweed is doing quite well, expanding in size - but not doubling in size every other day.. it's more of a "side salad" for the tilapia rather than a complete meal.. I'm feeding them crushed catfish pond pellets that are 32% protein and they love them..

The plants however are not doing too good.. nothing has really taken off, the soybeans look OK, and the vining tomato is climbing high, but without blossoms or fruit, and the squash has turned into a wilty, tiny leafed, spindly mess..

I'm hoping that it needs trace minerals and have been looking for Maxicrop plus Iron, but exhausted everywhere in town and ordered some online today..

I'll go out in a min and do a water test and shoot some pics to show you what's going on..
I think I also have a flood/drain problem after fixing a clogged drain last week..

Talk to you soon,
Joey

Ok- Here are the water test results.. I ran out of drops so couldn't test ammonia..

Outside Temp - 91F, 33C
Inside the Greenhouse - a hell of a lot hotter..
Water Temp - 80F, 27C

Nitrites - 1.0
Nitrates - 10
pH - 7.0

Nothing is covered with shade cloth, do these "full sun" plants need shade ??

Here are some updated pics !


Here is a new input pipe from the ST to the FT.. we felt having just the 90 at the end didn't stir things up enough.. so we added a pipe down to the bottom of the tank to really get things moving.. the cuts in the top break the siphon and splash water around for oxygen



The biggest tomato plant, looking very viney with no blossoms or fruit.. there are a couple of attempts to "clone" the tomato plant in the foreground on the right, that haven't really taken off (one in a rockwool cube did)



Some rather spindly looking squash and zucchini




More squash and zucchini




Looking down the GB from the FT (the basil has perked up a bit)



This side of the GH gets shade around noon, and sun in the PM - That's soybeans and peas climbing, and a pepper that looks pretty good, with some eggplant in the background




The eggplants look pretty good, but there are always a couple 10-15 aphids on them.. I squish them every morning, and released ladybugs but there weren't enough aphids to keep the ladybugs happy



This is the spot where I ran out of gravel.. I haven't been back by the place to get more, but it lets me see quickly exactly how much water is in the GB



Same shot with a butternut squash planted in rockwool and transplanted in the foreground



more climbing soybeans and peas, looking up the GB toward the FT



pretty good looking pepper plant.. I noticed some holes in the leaves early on, but that has stopped now (they were transplants so it may have happened before i got them.



Another shot of the big tomato, growing like a vine like crazy, no flowers or fruit yet.. I hope to hang it from the rafters..




The NFT system on the other hand looks awesome ! There are quite alot of small poop particles all over the inside of the pipe and the roots, and I am considering adding a sand filter - That's my ipod jack hanging at the top of the pic for size reference



More NFT, that big tomato is going to need tying up..




Butternut squash, mint, tomato... the usual suspects.




Here are the fish at feeding time.. I try to feed them 3Tbsp of food, 4 times a day.. but it usually ends up being 3 times a day.. there are about 50 tilapia


Let me know what you think or can see something obvious that I should be doing (other than Maxicrop which is on it's way !)

~Joey

After alot of staring and head scratching.. I decided that my flood and drain cycle wasn't right..

Here's what I had:
A huge pump blasting water from the bottom IBC to the top, overflowing into a 4" pipe and into the growbed which has small holes for a drain back to the sump.
Fill was 3 mins per hour, and drain was about 25 mins..

The trouble was:
I felt I was only turning over 1/10 of the water in the IBC per cycle, and the plants weren't getting enough goodies..

SOOOO I installed a ball valve in the bottom of the growbed, so I have one more adjustment in the system.
Now, I'm filling for 10mins (and turning over roughly 1/2 the tank) and draining for 10 mins every hour..

I still haven't checked the specs for power consumption, but in theory I think this is better..

How does your GB drain and fill ? Should I open the valve more and shoot for 15 mins fill and drain ?

Thanks again for all your help - I wouldn't be this far without you !

was it something I said ??

does anyone have an opinion about the timing of the system ??

most of the posts I have read dont seem to place too much importance on the flood and drain times. personally, I think the more water volume that actually flows through the media, the better.

Your tank turnover depends on your pump spec/flow rate... as much as the flood & drain frequency/period... and system method...

ie continual pumping, Chift Pist, and auto-siphon... or timer and overflow standpipe...

We suggest turning over the tank volume at least once per hour... in terms of flood & drain times... it doesn't matter that much...

And indeed, pump on time/duration in a timer system is often increased/decreased in relation to seasonal factors...

ie... perhaps 30/30 instead of 15/45 in summer or the tropics... and/or no pump cycles through the growbeds overnight during winter...

Indeed OBO's environment dictated the reverse... no pumping during the day, instead cycling through the night...

Less shade, more light.

I hope I can find a source in Israel on IBCs like that !

I would suggest smaller pump, longer cycle time to flood GBs,

from here on out its tweaking, little changes can make big difference.

Nice job ! Hang in there, its just going to get better.

Thanks guys !!
I'll keep an eye on the flood/drain..
My Maxicrop arrived today, so I'll be giving it a shot tomorrow !

~JOEY

I can't believe it's been a month !!
We went out of town, but all is going well.. the tilapia are growing and there is a tomato vine that is over 8 feet !! I have yet to get some tomatoes off them yet, but there are blossoms everywhere..

I put the tilapia in on 5/12 - the first month I fed them aquarium food .. and they were 2 inchers.. so I'm calling that 6/12.. the plants have taken off.. hopefully enough for an end of the year harvest !!!