Backyard Aquaponics
A place to discuss aquaponics

Good to hear Pete. Get them in the main system and then fingers crossed.

remember to keep feeding to a minimum why they are settling.
they need to get their little bodies settled to the chemistry first.


[psteve] Fair enough. I'd like to get a decent digital pH meter. The cheap Kekida one I bought is useless, so I've been relying on my interpretation of the API kit.

Milwaukee is about the cheapest 'scientific quality'. eBay carries them from a few US suppliers for around A$200.
But also google for direct sellers - cheaper via US direct in my experience. Lot of Australian ones are $300+
That gets you temp and pH with robust replaceable probes. MI105 / MW102 (pH/Temp) or MI805 (+EC)
eg. http://www.ebay.com.au/itm/Milwaukee-MW ... Sw65FXrOgp
or even (if you want EC as well for small amount more) http://www.ebay.com.au/itm/371022544219 ... EBIDX%3AIT but MI805 would be better to get temp as well.

But not cheap - those cheapies and pen sticks etc are just a bit of a con and probes <$100 are going to be hit and miss.
Particularly if you don't have proper calibration solution within your water test ranges.

Thanks for the support Guys,

I'm already thinking what the most likely causes were and considering how do it next time (in 4-5 months) for the IBC system 2.

BTW forgot to mention the water temp was 11.5 C in both tanks, so I probably had even longer to go before the ammonia became toxic than the bag. The water was becoming cloudier though.

I changed the pump cycle times to 15 on 60 off 24/7.
Sprinkled 15 grm Iron Chalate in 5 lt of GOTW (gassed off town water) for the plants with yellowing leaves.
I pulled the harvested Broccoli plant out and replanted with Butter Beans seeds.

I had a peek and they were hiding at the very back in the dark but one came out for a whizz around.

Pete.

keep an eye on the pump times over summer as DO will become important for trout as the water temps rise.
If in doubt may have to go up to 30-30 or something.
But you will have air running anyway I think ?

Go for some Asian veg - they like the warmer temps and a bit of humidity over summer.

you may also need to hold a bit of water for the veg on really hot periods if your beds get a bit warm.

Regarding pH meters. In some ways they are nice and they are more accurate but for as much as I do pH readings (not much) it doesn't seem worth it - If I was doing this professionally, I'd get one and I'd use it more often. With the frequency I do pH testing it's too easy to let the probe dry out while it's being stored, and that can cause problems or even trash the electrode. You can sometimes restore them so if it looks like it's toast you may want to try doing this. Here's a URL with a few ideas for doing this https://www.researchgate.net/post/How_can_I_fix_or_refresh_the_pH_electrodes

How long should I wait before feeding them?

Pete.

If your ammonia reading is zero in the tank you have them in then you can start feeding. You want to start with light feedings and work up gradually over a week or so BUT stop feeding if the ammonia starts going up too much (more than a trace) or if the fish start having troubles. Resume once it falls back to zero or the fish recover - you're mostly trying to get the filtration up to speed though - it takes as long as it takes . New biofilters can be a bit quirky so you need to watch it more now than you will later.

Spread the feedings out - it's better to have three feedings of 20 gms than one of 60. Less danger of a large ammonia spike.

I think we've nailed it this time.
Just checked the tank at 10.30 pm and there are no dead fish lying around and they appear to be cruising around in the bottom half of the tank. Fed them about 40 grains this morning and just before.

Pete.

Good news. As Scott said, just take it slow, and monitor :-)

With the weather warming the next few days keep the oxygen up.

Day 2 for Sy1 15 trout.

They're still there and looking bigger already, they hide at the back of the tank where it's hard to see them.
At feeding time I drop a few grains in per minute and watch them drift to the bottom, after 5 min a scout trout will whizz out an take a peek. Another 5 min and a couple more brave the light then a few min later the rest come out for the feeding frenzy at the bottom.

FT1 temp got up to 18 C today in 30 C amb. and windy conditions. FT1, FT2 & Water storage covered in white tarp.

I'm happier that these guys have made it.

Pete.

sounding like your system is OK, so just need to resolve your quarantine/acclimatization phase....

water volume is always a plus - that is a big positive that you have gained once they are in the FT.

The shade cloth etc may not be enough, may have to get some silvered insulation or something.
plus grow beds will heat the water up so keep an eye on things while you are still trying to figure the system characteristics out.

At what ammonia level should I stop feeding the fish?
It seems to be 0.25 ppm at the moment, the trit's are up a little but the trat's have lowered a lot.
What does this mean?

I've been leaving the lid up this evening before dark to encourage the fish to explore the lighter areas of the tank and get used to someone standing there. When I came back to check, I found about half of them swimming around in the top half of the lit end of the tank.


Pete.

Hi Pete,

I'd hold off feeding for now. It'll probably be back to zero in a couple of hours and you can feed again. Check the following -

1. Your last pH test didn't look conclusive to me and you need to do it again with both high and low range pH because it's on the border line between the two.

2. Water temp

Once you have these, check the toxicity level from the chart in the IBC of Aquaponics. It's not uncommon to have some ammonia especially with a new filter but keep it well away from the toxicity level. Algae can make the pH fluctuate during the day so if you have lots of algae take your pH reading with a grain of salt and just keep the level zero as much as you can.

I can't see any algae inside the tank.

I printed off the toxicity chart but am a bit confused on what the resulting numbers mean. Eg when the Ph is at 7.2 and the temp is 20 the result is 3.2. The next temp down is 16 and the resultant rises to 4.4 is this an increase or decrease toxicity? And is there another chart for the toxicity tolerances of specific fish?

Pete.

Pete,


The way I've always read that chart...



is that the numbers like your 3.2 ppm TAN at pH 7.2 and 20ºC and the 4.4 ppm TAN at pH 7.2 and 16ºC is the level generally considered toxic for fish. So when the temp goes up and the pH goes up it takes less Total Ammonia Nitrogen (TAN) to be toxic. And the reverse is that when it is colder and the pH is lower fish can tolerate more TAN before it becomes deadly.

There are other presentations of this idea out there and Free Ammonia Calculators. Here's a simple one just taking pH into account at 25ºC:



So in your examples, the 4.4 ppm means that it takes a little more TAN at 16ºC to be toxic than it does at 20ºc where 3.2 ppm is toxic. So the higher the number in the chart means it take more Ammonia to be toxic. The same amount of Ammonia in the water (ppm) becomes more toxic as the temps go up and more toxic as the pH goes up.

--
Sam

Thanks Sam,

but how much can the resultant value drop before it does irreversible damage to my trout? Ideally there should be a line going though the resultant numbers for specific species so we can see when we're getting close to the danger zone.

Pete.