Backyard Aquaponics
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I am planning to have a aqua-phonic system, but since I plan to use rainwater as my source I want to experiment first with goldfish and they are dying fast each time it rains and fills the barrel with fresher water.In farther away barrels they ae connected) that dont get as much fresh water they are doing OK. What can I do? The rain is from a baked-on-painted metal roof via a slime covered metal gutter, so I dont think its the metal. The Ph is too low, how much plain salt do I add to a 50 gallon food grade plastic barrel to raise the PH a notch? I need something cheap. Maybe powdered limestone? want to keep the mosquitoes out and need the fish to survive... Thanks for any help.

You don't use salt to raise pH.

You want a product with carbonates it, so it adds some hardness and pH buffering capacity to the water as well as raising the pH slightly.

As you went on to suggest, crushed limestone will do the job. It can be bought cheaply through garden centres as garden lime. Make sure it is regular garden lime and not hydrated lime etc, which contains zero carbonates. Regular garden lime is simply crushed limestone and will look just like coarse sand.

_________________
Mr Damage - a.k.a: Yabbies
Owner at Perth Aquaponics - Aquaponic Consultant & Trainer
Trade certified Horticulturist & Cert IV TAE

Thank you for your reply, I considered salt because I am told it is especially good for goldfish. But would you have an idea how much limestone to add for 50 gallons? Does it take awhile to work I don't want to add too much. If it takes awhile then what I think is right when I first add it and test, could get overly high later..

Hi Gardenan,

Each AP system is a bit different because of their source water and media being different. I don't think it would take very much to adjust your 50 gallon aquarium though.

I use crushed coral from a fish store in. I'm pretty sure it's more expensive than garden lime but It's coarse and I can put it in a fine mesh paint strainer bag then set it somewhere in the AP system (usually under a spigot or in the sump). It dissolves slowly so I use this to help raise the pH and if the pH starts going too high then I can remove the strainer bag. If nitrification is forcing the pH down too fast then I'll need to adjust with something else like potassium bicarbonate. If you want to try this I noticed someone made a video with some suggested amounts that will give you a starting point - remove it if the pH gets too high and put it back in if you need the buffering again .

https://www.youtube.com/watch?v=GLilfCxfVF8

the fish dying is 100% because water changes are too high each time it rains, because it doesnt rain constantly.

when there is a large gap in the rain, the water parameters change over time, so when it rains again, it all gets flushed away in one big hit.
that is what is killing the fish.

you either need to change all those little "barrels" to one proper tank or need to divert the flow properly between the barrels so one barrel isnt copping the brunt of the water change.

theres no point trying to buffer anything, because it will just be washed away next time it rains and the barrel over flows.
also, your PH isnt too low, unless you get acid rain of PH 5.5 or below.

its not called aquaphonics.
salt has nothing to do with PH
mosquitoes can be kept our with flyscreen.

is this a joke thread?