Backyard Aquaponics
A place to discuss aquaponics

Thanks Rupe.

I have 3 air stones pumping hard and water pumping through 400L of filtration when isolated.
Would I be better off changing the pump to a higher rate?



Trout seem happy but not sure that they are feeding much but I haven't kept a close enough eye and don't have enough experience with trout to know what to expect with their feeding. I am scooping a fair but out though.
I am waiting the arrival of an eBay purchase to test salinity. It's high though probably 5-6ppt at a guess. I have one air stone and lots of aeration from the return.
Will the trout need salt down to 3ppt or lower before they really hit the food?

If the trout are back to health you could drop the salinity back to 3ppt... which would benefit your plants....

Built a 2 IBC system for Brother-in-law today.

Similar to this:
http://aquaponicsgardener.blogspot.com. ... s.html?m=1
Ours has slight variations as we could not find all the same fittings etc.

Has 2 GB - 250L scoria + 150L expanded clay in each

2 Tanks connected acting as CHIFT PIST. FT/ST 500L each.

Cleaning the scoria in the trailer:


Filling the GB:


Final layer of expanded clay:


All cut and plumbed in 24 hours.

A couple more photos of the brother-in-law's system.

When i changed the pump coming back to the FT from the sump i realised i now had more pump volume which put my SLO to the limit. The tank didnt over-flow but water flows over the top of the T
I did some reading (see links) and it seems i should have used a 90mm pipe.
http://backyardaquaponics.com/forum/viewtopic.php?f=14&t=9844&hilit=slo
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=8973&hilit=slo

Now i need to find 90mm uniseal or equivalent & a hole cutter that big - i think i'm going to put this off for a while and put up with the slower outflow.
I threw a venturi on the return which slows the flow and adds more air.

Also, i've been away for two sets of 2 days and each time, one of the small feeder hoses to the NFT got bumped out and slowly leaked water. I returned both times to a drained sump.

This second time i have only filled the sump to a safe minimum - the result has been with less volume outside I am retaining water temperature overnight.

I have removed the isolation of the FT a night as it kept the FT warmer overnight but the FT temp would drop by about 2C as soon as I returned to full cycle - my thinking is that this temperature shock and probable Ammonia build up overnight is not worth it and have stopped isolating overnight.

If keeping the temperature up overnight is allowing for more feeding, you probably can't afford to isolate since ammonia build up could be a problem.

If isolating is simply to keep the temperature from Killing the fish and even when cycling is full the fish still are not really eating either way, then ammonia build up is unlikely and the isolation is probably worth it and not a problem.

Hiya happy, if your slo overflows down the top of the tee then maybe all you need is to put more holes at the base of it to increase the volume lifted.
Just a thought.

Skeggley, I think the problem would be on the outlet part of it, rather than the inlet. The water level is increasing due to not enough flow through the SLO, so increasing the top outlet tube size would be a better first solution if you didnt want to go to a larger pipe. Flow will increase automatically anyway as the pressure increases, but increasing the flow in the vertical part is impossible, as the horizontal outlet pipe is governing the flow, which only increases as the water level, and therefore pressure, increases.

Originally I set up the isolation because I was worried about low temp causing deaths. But the temps have straight high enough for them to keep feeding.
TCLynx you are right that the feeding has now made the Ammonia load the highest risk.
Time for me to add the extra filtration rather than playing with isolation idea!

I have been hoping that your thinking is right but have not tested it. It would also be the easiest solution!

I think you are right!
My outlet is very high on the tank too. So as the water level rises it quickly runs the risk of overflowing.
The complication is that the outlet goes straight into 2 barrels for filtration and out to grow beds through 25mm pipe.
So increasing the outlet diameter and flow will have flow on effects that I don't want to deal with ... But may have too soon.

branch off to that extra filtration you need to set up then.

Visited my brother-in-law's system and he has planted a bunch of seeds (still to germinate), transplanted lettuce and strawberries from the garden and are doing well. He has also blackened out the fish tanks with black plastic and cane - looks good!
Lots of visiting family and friends took a liking and interest.
I have given them a temperature gauge so they can let me know when I can bring some perch down to them (its currently 12C).
Also, dropped off some Azolla and duckweed to get growing.

Back at home:
I haven't been spending much time on the system, just quick feeds 2-3 times per day, leak, pump, temp checks.
Main system has been keeping its temp up around 17-18C with less heating required (thanks to a very mild July). Water clarity is poor but I'm not too worried about that - I am thinking of filtering the return just so I can eyeball some more of the perch. They are feeding vigorously and consuming about 40-60g/day of pellets.

Trout (8) are noticeably growing and looking healthy. I have connected this tank to my 48 hole NFT which I have put a bunch of seedlings in (lettuce, rocket, parsley, pak choy, Chinese cabbage, broccoli). current temp is 16.5C. Carrots and beetroots are coming up strong. Onion didn't come up at all. Lettuce and rocket seedlings mostly got smashed as they came up while the salt levels were high. Salt reduced to approx 1.5-2ppt as I had some water losses while away and while getting the NFT working correctly. Just added more lettuce, pak choy and rocket seeds.

I finally got the evacuated tubes solar heater connected today. Connected it to the 500L tank with Azolla, duckweed & shrimp. Current temp 16.5C.
My hunch is that I should have just made own with rolls of black pipe (and still plan to when time allows)

Sprayed the strawberries with ecofungicide and removed badly diseased leaves. Most plants in the AP have 5-10 flowers each while there are no flowers on the strawberry plants in the dirt garden. I wonder if its the 18C water bringing on the flowering?

In the last week I have added another 500L grow bed but the use of cheap expanded clay was not a good choice as it floats and leads to the gravel bed shifting significantly - to the point that it buries transplanted seedlings.

The new GB is attached directly to a new second 25mm SLO.
This has allowed me to take the restrictions off the main pump from the sump to the fish tank.
The greater flow has lead to the fish tank water clarity improving significantly.

The strawberries are producing a heap of flowers but there seems to be a lack of pollinators and am still waiting for my first strawberry. Veggie growth had accelerated over the past few weeks with warmer weather. Celery, rainbow chard, parsley, coriander.
The local possum is also coming around for snacks on the increased greenery on the uncovered NFT systems.

Trout system had a pump failure because I was messing around with the bell siphon which lead to the GB overflowing and a loss of water. Thankfully the pump
Trout are growing really quickly and it seems like they are noticeably bigger every day.

Jade Perch are feeding @ 80g/day - I've noticed a big size difference now that the water has cleared and I can see them as they come up to feed.

Feeding rate has been 2-3 times per day lately.