Backyard Aquaponics
A place to discuss aquaponics

The chart here (which is also in the IBC of Aquaponics PDf) will show you what he's talking about http://ibcofaquaponics.com/information/tables-and-charts/

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How odd that we don't read and understand.. I had to go looking for that pH figure..
thanks for pointing to that actual figure GG.. and when you look at the chart of PH-VS-TEMP-VS-TAN (total nitrogens)
You see how little scope there is for any extra ammonia


PLUS ONE to your observations GG...

Sounds like reacting to an initial death created a cascade calamity.. the pH likely should never have been at 8.8..
6.5 seems to be ideal..
Get some Hydrochloric Acid..

BTW.. for you brighter chemistry types.. what of Phosphoric Acid, and especially Phosphamic Acid, which I have as a crystalline salt for dish-washer descaling..
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If they all died within the week, I'd also look into how you cycled the system.

It can be done with or without fish. But you need to keep a close eye on the ammonia/nitrite levels, and feed accordlingly. If you put in 130 fish within a week, I'm guessing it didn't get a chance to cycle properly.

And then it's just a matter of time.

I'd recommend doing a complete fishless cycle first, wait for ammonia/nitrites to be completely gone before attempting to add more fish. Find something like Charlie Carp (ground up fish) and cycle with that.

And for Canadian climate, unless you're in a really warm climate part, don't get Tilapia, try for the trout.

Rainbow and brown trout are definitely not native to Australia!

I don't have zinc.. no steel roof, well is 40ft from the house and 100ft from septic. there is no chloronation. I will upgrade the pump, which runs for 15 min then off for 30.. i have it on a timer.. should I change that?? I have a smaller pond pump breaking the water's surface, and currently I do not have my airpump running as it is too small and I need to get a bigger air pump..

the Fan is for air circulation as I haven't installed proper venting in the green house yet... I open the screen door with a saw horse to keep the door wide open and the fan moves the air... the hotest it got in the green house was 50 degrees last week.. but Its been fishless for 3 weeks..... once the last body was removed, I drained the pool, gave it a scrub, cleaned the pond pumps, removed the air pump... and refilled the pond, added pond water conditioner, ammonia, and what I had left for aquarium salt.. which probably didn't make much of a difference......

This was over may and june.. and the loss started the end of june.. system cycling started in middle of april.. since greenhouse was maintaining a temperature of 15-20C. .. the combined total is 130 fish.. the last batch was lost first week of July... the system is now fishless

THIS IS WHERE MY ISSUE COULD BE... Dead spots..... sounds right because I did find poo/ and uneaten food in dead areas of the pool .. like a whirlpool, things would sit to a certain spot out of the current.. I will pick up a better pump for airation, and also look at a better way to keep the water moving so it doesn't stagnate...then it should begin to balance out.. I had Nitrites and Nitrates by end of april/ first week of may when I added the the first 40 fish.. then i lost about half(i thought they were all the goldfish were dead when I got the chilids for free.. then the chichlids got added, things were great.. gave me a total of about 70 (1-5" for the fish and 2 16" plecos") fish in 500 gallon pond/pool..... then they all died.. then waited two weeks to recycle.. I had Nitrites, but no nitrates, ammonia was 0, PH was 8.... I added the 30 or so free 2-4" gold fish.. they lasted about a week and all were dead...... so no it's fishless.... I will give it another week and see if i can get the cycle to start again.. will keep you guys posted!!.. and I will only get two test fishies.. lol THANK YOU!!!!!

If you are starting from scratch, you really want 4-6weeks for the bacteria colonies to get established properly, so they can deal with the Ammonia load of whatever number of fish you put in. Being able to deal with waste from 2 small goldfish will not prepare it for adding 40 larger fish in, and then feeding to demand.
If the system is fully cycled, ie bacteria colonies of sufficient size to handle the fish waste load, you should see rapid acidification (if you don't have a large amount of carbonate buffering in the water) within a day or 2 of adding a dose of Ammonia equal to the load from your about to be introduced fish.

Thanks! I will keep it fish less until I get the acidification happening!

Hi Firediver, as Scotty said, you need circulate the volume of your fishtank through your system ~once an hour. This means if you are running your pump 24/7 it needs to be pumping at least 500gall/hour. If you are only running your pump 15 minutes on and 30 minutes off you need one that can pump 1500gal/hr. Circulating the water at this rate generally provides sufficient aeration without the need for additional air pumps. If your 350gal/hr pump is only on for a third of the time, your system is seriously under circulated and probably oxygen depleted especially with build up of waste in 'dead' or stagnant areas. Even with your current pump on 24/7 its probably not enough. You also need to do a timed bucket test to see how much water is actually being pumped, it could be a lot less than the stated capacity due to head height and frictional losses.

Do you have a means of removing solids from your fishtank? Generally folks use solids lift overflows (SLOs) if their pump is in the sumptank, or a pump that can handle solids in the fishtank. The solids are broken down in the GBs over time, or some folks prefer to remove them via a separate filter. The return water from the GBs is directed to cause a swirl in the FT that gently moves solids towards the SLO or pump.

From snippets of what you have written, I am not sure that you understand the cycling process. It is simply building up your colonies of bacteria on your media to provide sufficient biofiltration to cope with the ammonia load your eventual fish population will produce. You can cycle a new system in several ways either with or without fish (check out IBC of Aquaponics). The important thing is that you are running your system (pumps etc) as it would with your fish, you are providing a source of ammonia to establish and feed the bacteria, and you are monitoring to determine when cycling has completed. Generally, to confirm that the system is cycled, you should be able to add enough ammonia to provide 1-2ppm in your system and have the ammonia and nitrite readings back to zero within 24 hours. Both ammonia and nitrite are toxic to fish.

+1 on what Gunagulla said about cycling, and I would add that your ammonia and nitrite levels should return to zero within 24 hours of dosing with ammonia.

I agree with what has been said about cycling, but one thing that I haven't seen raised is the original source of the high pH.
What brand hydroton did you use? I recall someone else on here struggling with pH and other issues for a length of time before determining that the brand of expanded clay they used was treated with something to raise pH and help the typical home hydro gardener with their specific crop.

Good luck.

Local nursery sold it, one bag was hydro corn and it was crap, the rest was Huston. The local nursery sells everything you need for hydroponics, and now just learning about aquaponics

I first had a die off in the middle of February due to cold temperatures. I flushed my FT, swirl filter and sump.
System is 330 gal IBC tote Fish Tank
55 gal blue barrel swirl filter
330 gal IBC tote in ground sump
14 half barrel grow beds, pea gravel media (gravel is about 1.5 inches from the top edge of the half barrel), auto siphon. Water usually stays about 1 - 2 inches below surface, but sometimes floods. So there is about 730 gallons of water in the system. Two 1200 gal/hour pond pumps circulate water 24/7. There is a handful of red wiggler worms in most of the grow beds as well.

I got a deal on Blue Tilapia and bought 100 1/2 inch fingerlings. I kept them in a small tank in the house until they got to 1.5 inches. My system had been cycling for 6 weeks with no fish. I added about 10 fingerlings every 4 days until all 100 were introduced. All was good, I achieved good growth of peas, kale, collards and leaf lettuce also tomatoes, and the fish guickly grew to 2 1/2 to 3 inches. I suspect at that point I should have thinned out the tilapia population. In one day the peas and kale started showing yellow tint in the leaves and I noticed lethargic fish gasping at the surface. I took a water sample of my well water and the fish tank water to a local tropical fish shop where the owner is familiar with aquaponics. My well water tested good at 7.2
The fish tank water was really acidic at 6.0
His advice was to replace 1/2 of the fish tank water then monitor PH making adjustments with 1/2 tablespoon of baking soda to the sump every hour so as not to make a rapid drastic change.
Unfortunately the die was cast and over the next 48 hours one third of the fish died off. I continued to slowly adjust the PH with the recommended method and got it to stabilize. The fish started acting normal and the plants began getting normal coloration.

I now have no idea what is the max fish population that my system should sustain. Any suggestions would be appreciated using the above system description.

Thanks

emp1953

Yes, sorry, but you likely know what I meant..
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Number of fish.. ??? ... the accepted rule of thumb ... I fish per 25L of media..
Now this is assumed to be for a typical system where solids are sent to the grow beds..
So where you have an efficient solids filter, the ratio simply must be different..

I still seek a Rule-Of-Thumb for when ALL the FT solids are removed...

Its logical that if all solids are removed, via filters, then there is a deal less bio-filtration needed....
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I don't know if I did my calculations correctly but I come up with approx 250L of media per grow bed. They are half barrel beds. The barrels are 880mm x 620mm. media is about 1.5 -2.0 inches from top of the half barrels laying on their side.