Backyard Aquaponics
A place to discuss aquaponics

Stage 2 is underway!

The Polycarbonate for the greenhouse has arrived!


There are 5 sheets of 6m x 2.1m x 4mm double skinned polycarbonate here.
Better get the wood ordered for the frame!

I'm beginning to feel that maybe I put too many plants into my IBC growbed!



Anyway, good news! The ammonia level has started to drop. Also, the water looks only very slightly green now (algae dying off).
One weird thing with the latest test results is that the pH is again around 6.6 when it was 7.5 only 4 days ago. Could it be the time of day I am taking the results? Or is the dying algae causing the drop?

So, 28th July results are (test from 24th July in brackets):
pH = 6.6 (7.5)
Ammonia = 1ppm (8ppm)
Nitrites = 5ppm (2ppm)
Nitrates = 40ppm (15ppm)

Now I've really got to get serious about arranging to add the fish!

And just for fun a side-by-side shot from 26th June and 28th July

OK. So this has nothing to do with Aquaponics but in our search for a more sustainable life....we got our new 100% electric car! A Renault Zoe called Joshua (according to my wife!).

New water test August 1st (Day 37)
pH = 6.8
NH3 = 0.25ppm
N02 = 0ppm
N03 = 100ppm

So everything looks good with almost all the ammonia being transformed into nitrates (via nitrites).

So, I have added 6 Goldfish! We actually have aquaponics now.



Some of the Courgettes and Tomatoes are looking good too.

Right. Fish have been in just a couple of days and the Watertest is showing the following.



August 3rd - Day 39 (August 1st)
pH = 7.0 (6.8)
NH3 = 0.1ppm (0.25ppm)
N02 = 0ppm (0ppm)
N03 = 160ppm (100ppm)

Those test results look just about perfect!

As to your question a while back about pH and time of day and algae.

Yes, when algae is involved you can get diurnal pH swings since during the day, algae will consume CO2 from the water (CO2 dissolved in water is carbonic acid which is a weak acid but still strong enough to affect pH) elevating the pH through the day. At night when there is no light, algae will give off carbon dioxide to the water lowering the pH.

When you have fish in a system with lots of algae, extra aeration should be added overnight to keep the algae from consuming all the dissolved oxygen and suffocating your fish overnight.

Hopefully your algae problem is nearly over and the pH will settle down to the normal tendency to drop over time.

Also, if the water you top up with is hard water (has calcium carbonate in it) it could cause your pH to go up when you add top up water and then as the calcium carbonate gets used up the pH will drop over time.

Hows the car going, Alastair?

Some good growth there mate! I am pretty sure everyones first system looks like a plant explosion

So, we have Courgettes! Here is the first one (but lots more to come).




It is going very well. We never realized how much noise other cars make, until we had a completely silent car!

A completely full tank is about 2 Euros ($2.60) although of course you only get 140km for that. Since our electricty is only 7% generated from fossile fuel, this is a very real saving on CO2.

New Watertest. All seems to be maintaining okay for now. Not adding any plant food just fish food. Algae definitely decreasing but not yet gone.



August 7th - Day 43 (August 3rd)
pH = 7.0 (7.0)
NH3 = 0.1ppm (0.1ppm)
N02 = 0ppm (0ppm)
N03 = 120ppm (160ppm)

So, we now have polycarbonate, wood, tools and piping for the next phase (see here for recap on plan)
Looking to start Monday!

OK. So Algae is now all gone, well in fact a lot of it is lying at the bottom of the tank. All 6 goldfish are still alive and well. The fish seem to be eating some of it (or it is spontaneously diappearing!). pH seems to have gone back up but I guess that might be due to decomposing algae!?



August 10 - Day 46 (August 7)
pH = 7.5 (7.0)
NH3 = 0.2ppm (0.1ppm)
N02 = 0ppm (0ppm)
N03 = 80ppm (120ppm)

The pH being back up might simply be the lack of the living algae pumping CO2 into the water overnight.

If the pH actually went up due to decomposition, it means you may actually have anaerobic decomposition going on which can be bad so sniff around and make sure you don't have a stinky anaerobic spot somewhere.

OK. So from this point forward I shall be concentrating on covering the new Greenhouse Build.
The IBC system is still going well and just provided two more cucumbers today!

It will be a 6m x 3.5m Polycarbonate Greenhouse coupled with a 2000L fish tank inside the existing Garage.

There will be 3 gravel media beds plus one raft system as well as NFT tubes and Towers.

Here is the overview diagram.