Backyard Aquaponics
A place to discuss aquaponics

This is a fantastic site I have been reading it for months now and have tried my hand at a system. As I've said we are limited to where we could put in the system and where there would be enough sun as well. Our back yard is very shaded with large tree, great in summer, so I wouldn't have it any other way.

It's a small system with a 200 litre tank and 4 down water pipes. North facing posistion with full sun for around 6 hours a day. I now have shade cloth over the wooden structure because the plants were being burnt in the summer sun. Rainwater from tank behind. Pump is probably too large for this system but I need the max head to get water to the top rung. Timer turns pump on and off. Free drainage back to the fish tank from downpipes.

The system has been running for around 8 weeks now.

pH 6.8 and stable
ammonia/ ammonium <.25 or near enough to Zero
nitrite 0
nitrate .25

I started with two gold fish and have worked up to nine now ranging from 5-7.5 cm body length. They are very healthy and relaxed.

Can't say the same for my poor plants though.

The rosemary, thyme and 1 strawberry are healthy and growing new shoots. My cabbage, capsicum, basil, corriander and parsley are just hanging on. No new growth and yellowing leaves. The sage and chilli are all but dead.

I think it is a nutrient problem. I have given 2 good doses of seasol. Ph is in a good range for nutirent uptake. I have been feeding the fish twice a day now for 2 weeks. I put a good dose of some human consumption iron gluconate dihdrate, that my wife took afer her pregnancy. (Blooms organic Iron Plus) yesterday.

Some words of wisdom would be much appreciated.

Here's a picture to show the happy healthy fish. Water is crystal clear and have had no problems with Algae to date.

Looks like a nice setup there arbor. A pity about your plants. I'm not an expert at all with plants, but if your strawberries are doing well, it could be a straight nutrient problem. Strwberries are very hungry, and your Nitrates are low(I think) so there may be none left for the capsicum and cabbage.
It could be a potassium problem (but I know no more than I have read on this forum about potassium) you can add potash or even bury a banana (washed, see potassium threads)
I trust you have continuous flow? those growbeds look too shallow for flood and drain.

Hi Arbor

your system looks great!

you have picked a quiet night to launch your self onto the forum but I am sure that in no time you will have assistance from fellow members who know what they are talking about oh! that wouldnt be me by the way. no yet at least

An excellent start! Welcome, arborlow.

I'm inclined to say it's nutrients, too. KP is on the right track, or you can add more fish, of course. Maybe both.

Hi Arborlow, great to have you here with us

Everyone else has pretty much said what I would have said. If the pump is too big for the system, that is, too much flow into the channels, you can split the flow and run some straight back into the fish tank for extra aeration.

Do you have constant aeration in the tank? If you don't, you might look at adding an air pump before you add more fish.

Have fun with it

I think you may have a problem with root space in the downpipes as the plants get bigger - I am using 125mm pipe cut in half with hydroton, and the water now starts to overflow.

0.25 nitrates. VERY low.

remove the siclky plants and keep the ones doing OK. either that or increase your fish load / feeding rate.

you've gotta be quite careful in your setup with root rot IMHO.

try and ensure very hight O2 in the tank, this will help with the above problem.

Outbackaussie
I have worried about the root problems from the start but was unable to find containers tall and thin enough to fit in the dimentions of my space. There's just enough room for 1 person between the system and the back fence.

I'd much prefere to have a flood and drain system. (Don't like reinventing the wheel) I tried flood and drain with the pipes but only about 1/4 would drain out.

Steve
I think you are right and should increase the fish load. I've searched the site for root rot and I think it is a problem too, but have not found much info. What is the major cause. I have an airstone running in the tank at odd times especially when the pump is not running, will that be enough.

Root rot is caused by warm wet conditions and not enough oxygen.

Just run your airstone all the time. Also ensure that there is good splash on the water return to the tank. See if that helps. Also, keep the water shaded if your temps are getting high. Warm temps decrease dissolved oxygen.

dont have too high a flow, dry at the top and wet at the bottom is prolly ok.

you will invariably get dead no flow spots which will become oxygen deprived. but then i guess that threre is a theory that higher flow would minimize this. maybe try really getting the O2 into the tank first then re-assess

An update

Firstly I have doubled the fish load with no problems. 18 fish now. I hope my nitrites and nitrates increase to feed my plants. Feeding fish twice a day. Ammonia still 0 nitrites 0 havn't done nitrates yet

I have set the timer to run 2 hours on and 2 hours off generally 24 hours a day to try and allow some Oxygen down to the roots. Chilli has come back from the dead and other plants are budding nice new green shoots. so this strategy seems to be working at present.

Have added another 40 litres flood and drain above the fish tank. have used a tube within a tube siphon made after reading the section of siphons. Having some problems with dribbling though.

Siphon starts well with high flow but does not turn off. on low flow the siphon only dribbles out. how much space should there be between the inner tube and the top of the outer? I think this is where my trouble lies.

good to see the fish load helped out!

Let's see pics of the siphon. I think you have a pipe-in-a pipe siphon from your description...did you include a little tube to help get air in to break the seal?

Here's some pics

I tried again today needs fast flow to start it up then it won't turn off, just keeps flowing out at the rate of the inflow. I can hear the little air tube suck in air but it obviously is not breaking the seal. When flow is slow it finds an equalibrium and will not begin to siphon out at a fast speed to drain.