Backyard Aquaponics
A place to discuss aquaponics

That is what I did, a little trout net gave me more than I needed in one scoop.

I don't know if rivers are warmer than tanks but figured if I get them from the area they are more likely to cope with local temps. I am really too lazy to change fish every 6 months.

Built a worm bin last night
Also found a local red wiggler supplier R50 for 200 (US$ 4.65 AUS$ 4.98) Bag of bedding for R25

This is the inner bin, still need to get a tap for the outer bin



Will pass the time while I wait for the Water Chem roller coaster ride to be over. PH was 6 again the rest was maxed out. on my scale at least.

So while passing the time waiting for the water chem to come right, I got to thinking...
I have a left over IBC well most of one. It's missing the top 200mm.

I was going to use it as a rain water tank but the mozzies will love that.

What if i use it as a deep water culture tank?
Are there limits to the depth of the tank?
If I keep it as is, then I don't need a stand, an overflow can gravity feed back to the sump.
What are the pro's and cons to adding another 900l to my system?
Are there any funnies about DWC I would need to know.

If I put tilapia in there would the eat the plant roots?

There is no limit to how deep you can go. In fact deeper means the roots are less likely to get gunked up. The tilapia would likely eat the roots. With large enough net cups, the better term might be trimmed. The thing to remember is that DWC likes to act like a settling filter. So it is best to make sure the water is well filtered before it gets to the DWC vessel.

Thanks it will be right at the end of the run and I'd have space to add in another swirl filter and use a SLO for the return to the sump tank.

Do I need to add air stones into the DWC vessel?

Time for an update.

Decided to add a Deep Water Culture tank to compliment the grow beds.
Figured it would be a nice addition and it will boost the water volume by just under a 1000 liters.

Figured it wouldn't be too much work ... right

There was a last piece of precast wall left adjacent to the beds and figured it would make a nice platform.
Sorry for the hazy pic.



Had to make that little retaining wall at the back from reclaimed pallet wood because that is the entry point for the border collie's race track that stretches all the way round the perimeter. She kept smashing soil back into the troughs, she'd come belting through the bushes and slam on anchors when she saw me there.
Had to varnish the planks (ugh I hate painting stuff) because it's not treated wood. Hopefully it'll last a bit.

Confession time.
The DWC project is an attempt at distraction. I'm 32 winter days into the cycle and the water chem is still seriously fish unfriendly, it's been 13 days since i added any pee.

As per my previous posts the PH started falling, when it hit 6, 13 days ago, I added a stocking of oyster shell grit. PH fell to 5.5 the next day but stayed there for the last 10 days

The ammonia shot up to 5 (max on chart (MOC)) and stayed there for a few days then started dropping, went down to 1 for 4 days but now popped up to 2 again for the last 3 days.

The Nitrite shot up to 5 MOC and stayed there for the last 11 days, there's no waiting 5 mins for the test to get to the colour. Just goes red as you put in the drops.

The nitrate is a similar story, 100 MOC for the last 23 days turns to maroon soup as the drops go in.

The phosphate is also MOC at 10 i have the cover covered with an extra layer to keep light out of the tank and hopefully avoid an algae bloom.

I think I over dosed with iron, sitting at 1 MOC, test book says that above .5 mg/l is harmful to the fish. Hopefully when the dwc tank comes on line it will dilute this somewhat. Currently ST + Ft 1400 liters.

The KH carbonate hardness of the water is 2
And the GH general hardness is 13 or 14 whatever these mean. Had the tests in the kit so I did them.

Copper was 0 so that's a good thing and the plants are doing really well

Has anyone tried something like this? ... Besides these dudes of course?

That spacing is okay for seed starting, but your plants will need more space as they grow. Those little net pot covers are popular in hydro. I am sure they are good for keeping the algae at bay.

Thanks Ron..
Was thinking of using a 7 - 8 inch grid to space, some pots or cool drink cups with some of those spongy jobs stuck in the top. dunno where to find net pots

Need to find a place that sells foam from which i can build the raft.
If i use closed cell foam like that, I could use the punch outs as the caps

Or, you could use the punch outs as the plant holders...

Hey Ron,
My PH started off at 7.5 and was fairly constant till it started dropping rapidly. When it hit 6.5 you suggested I add shell grit to the tank.
This I did, stuck the whole bag in a stocking and suspended in front of the pump.
The PH dropped another notch to 5.5 and has stayed there consistently since then - about 14 days.
Should i do something to buffer it back up into the 6 - 7 range

Temp range 9° to 12°
Ammonia is fluxing between 1 & 2 mg/l
Nitrites is Max on chart although last night it took a while to get to red rather than instant
Nitrate is maroon soup

Yea, potassium bicarbonate, brickies lime, and some other bases can be added. Slowly if you have fish, quickly otherwise. Believe it or not, it can be a good thing that your ph wants to drop so much. Calcium and potassium need to be added sometimes to correct decencies, and they raise ph.

What is this mix 50/50
Hydrated Lime / Potassium Hydroxide - (Caustic lime.)

Have you heard of this stuff

I have heard of it. There are threads that talk about its use.