Backyard Aquaponics
A place to discuss aquaponics

A pH swing of that magnitude in itself would be detremental to crustacea... and probably fish as well....

I added some Potassium BiCarbonate to my system yesterday... partly to buffer it back from 6.2..... accidently dropped a "lump" in.... about twice as much as I should have....

pH went from 6.2 to 6.8 in a couple of hours.... tonite I found a dead fish... coincidence??

In general though... there aren't many fish or crustacea that like prolonged exposure to pH under 6.0...

You need to buffer back.... either a series of water changes or some Potassium BiCarbonate... for immediate affect..... and the addition of shellgrit for a longer term buffer....

Might sound strange but do you have any tree limbs around...
prefer dried? Bit more like a river

Have water temps remained the same?

Hi everyone, I lost all but one Marron (lost 71 ) It's hasn't seemed to affect the Silver Perch. I did some trials last night dosing 10litre buckets of water with Bicarb soda, untill i achieved a ph increase from below 6.0 to about 7.0. I added about 170grams of bicarb to my system (4000litres) and the Ph stabilised at about 6.8 after 3 hours of testing. This morning I checked the system and went off to work, by the time i got home the ph had fallen again to below 6. Buffered again with bicarb soda and added a 20litre bag of seashells, Im hoping that the sytem may start to naturally buffer now
The blue tubs that i use for my grow beds are food safe approved and I haven't added anything to my system lately. Im thinking that the biological cycle has kicked in and pulled the ph down. I do have huge temp fluctuations during the day often upto 10 degrees. top end about 27.

Does anyone have an oppinion on the amount of seashells required to buffer my system???
P.s. I have really appreciated all the help and suggestions from fellow BYAP enthusiasists, I hope to be able to contribute myself later as I learn more.

Marron don't like/die in water over 26c ish
possible cause of death I'd say or at least damage to organs.

From what I hear buffering with seashells,
(and haven't had any need or experience )
The shells sit in the system and give off CaCO3 ??? (gets used up/dissolves)
when the pH needs buffering.
(I will be corrected )

Too much buffering will give you hard water
and plants wont take up nutrients as well as could be expected
and fish might not thrive as well.

We need to workout why the pH is so high from the start..
maybe pass it through a beach sand filter and add salt to 1ppt
to give some minerals and the bacteria will have something to colonise with

If your water is out of whack there is a reason
Just need to find why

Thanks c1 for the advice, it's posible that the marron did die because of the high temp I never really thought of that.
Cheers Clint

Spot on C1....



Not so much... "too much buffering"... will give you hard water...

But the wrong sort of buffer will.... and using too much Sodium BiCarbonate is the wrong buffer...

You shouldn't add too much sodium bicarbonate, because high sodium levels in the presence of chloride are toxic to plants.

There are several basic compounds that can be used to neutralize acid in an aquaponic system. At the University of the Virgin Islands, they alternate between calcium hydroxide [Ca(OH)2] and potassium hydroxide [KOH].

CaCO3... (shells, shell grit) is the easiest and cheapest way of adjust pH... without affecting hardness... but it's like a "slow release"....

Potassium BiCarbonate... is a quick, relatively cheap buffer... with the benefit of Potassium for the plants...

Buy a certified organic product called "EcoRose".... from Bunnings....

Use sparingly.... a tablespoon in a 1000L.... willl move your pH by about 0.4 points... in a couple of hours...

I was waiting for the slap but didn't get one yet

All things being equal your water should be pretty stable,
and is why I question it.
how much top up water are you putting in?

I have only topped up twice since I started the system about 250 litres both times just to bring it up to the right height in the tank. I haven't seemed to have fixed the ph issue, back down to 6.0 again this morning. I think i will wait for the seashells to bring the ph back up slowly rather than shocking the system everyday. On a different note we finished the strawberry pipes today.

Just need some strawberry plants for them.


Cheers clint

Geez I have a heap of runners here
I don't see a trip to Perth soon
Soon it will be too cold for strawbs but you have the hot house
situation there
If you topped up 250 ltrs x 2
Maybe you could add a few litres each day rather than
chucking in a heap.

Clint if you would like some strawberry runners pm me and you can pick them up from the shop, I have quite a few in the pathways of my vege/ permaculture gardens that I can dig up.
Last year I potted some in straight hydroton and put them in a growbed with moving water, they flowered and fruited on their own.

Thanks Faye I will Pm you , I tried 3 different shops this afternoon but know one is stocking strawberrys at the moment. Cheers Clint

Tis because it will be cold soon Clint
You will have them under the roof lights warm as toast

Wow it's been a long time. Everythings growing great, The ph eventualy settled, the answer was too bury my head in the sand and stop testing, It worked perfectly and everthing evened out. haha
I thought I would put a few new photos up. We have just started to eat the tomatoes and sweet peas.

Great to hear it settled down. Looking good, will be interesting to see how the tomatos fair over the next few weeks. I have been contemplating throwing a few in at school just to see what happens over winter.