Backyard Aquaponics
A place to discuss aquaponics

This was a small system that me and mum decided to test out aquaponics in.
We used an old goldfish aquarium for the fish tank which is 700mm long x 200mm wide x 400mm deep. For the growing beds we used 3 and later 4 90mm PVC pipe cut at 800mm's long and attached caps to either end. We then cut a long thin channel in the top of each and filled this with cracked pea gravel. However we soon had algae growing profusely and the system had poor drainage and very little aeration.
The plant growth wasn't ideal neither were the fish casualties. So we changed the growing bed completely, we ditched the PVC pipe idea and used a large black tub which we happened to find at Bunnings!! It measures 700mm long x 500mm wide x 140mm deep
We are using a small fountain pump which pumps through 19mm poly pipe and distributes the water around the perimeter of the bed. This then drains through a small standpipe in the middle of the growbed directly into the tank. The system runs 24/7 and I have not yet seen any difference in growth or health of the plants to my other systems which cycle every hour.
I have attached some pictures of the new setup and some test results.

Does this system flood and drain or is it a continuous trickle?

This system is a continuous flow.

The picture of the plant growth two weeks later looks like the water is green . . however it is just the sides of the tank and the water is crystal clear.

Although I have recorded fluctuations in Ammonia, Nitrites and Nitrates . . which I am a bit concerned about. Especially the ammonia. However none of the fish have died since we improved the system . . . which is always a good sign!!!

looks like a nice little system... good job

I didnt notice before, but bring that PH back up straight away - at levels below 6 your bacteria will die rather suddenly and crash the whole system.

also pretty drastic that your air temp droped from 28.4 - 16.8 over 3 weeks, winter must have hit you pretty fast over there.... where every there is

Air temp is very random where I live.
Im in Western Australia in the middle of spring. Two weeks ago we were having 35 degrees Celsius last week we were at 10 degrees Celsius and now this week we are back at 25 degrees!!!!
Usually gets cold at night as we are in a valley but then it heats up rapidly during the day . .

Pretty much all my systems sit at around 6 and the plants and fish seem very happy...

Mine ran for almost a year at 6.4, didn't explode.

+1

Note - I dont usually say things like this, if I have not seen it happen.

Looks like half way through cycling. You must have chloride in the system else the fish would be stressing with the nitrite.
I'm with OBO in that it it dosn't look like the system is buffered. Stick some shells in the FT to bring the ph up slowly only worries are if you get another ammonia spike.

BTW great work with the log

But how do you know it was pH that caused it and not some other aspect, while the pH just happened to be at that level? Like I said, my systems have been at or below 6 for many years, and perform without a hiccup. That's multiple systems, and for many years, so I don't think it's right to throw people into a panic about crashing systems if their pH hits 6.

The fish are goldfish, 6ph would be just on the edge. OBO said below 6. There is algae in a small tank, ph could be varying depending on the time the reading is taken, buffering would not hurt.

OK I had a rethink on this because it sounds argumentative
Mitch can you measure the ph midday, if the algae is having any effect the ph should be higher?
A very very small amount of salt just to hold the nitrite, but not enough to slow the plants (nitrates getting up there). A little more O2 cause the fish are going to the surface. And if the ph is low (average) one small washed shell to buffer the ph.
Stuffed if I know what to do about the temps.