Backyard Aquaponics
A place to discuss aquaponics

Sounds like you're playing "guess which cup the pea is under" :albino:

PH is a weird thing. Mine has been 7.4 or so for months. No shells, grit or anything added. I can only assume the gravel may be helping to buffer - after all I have no shortage of nitrification ans stuff going on.

you must be happy with that VB, maybe the type of gravel you are using is doing the trick.

It's just basic drainage gravel though . Maybe the town water is heavilly buffered. May notice the difference when I get my rainwater tank in and use that water for the AP.

Got my 18,000 litre tank last week. Will be months before I get around to installing it

Steve, I reckon that's spot on

I rhink this is how it works - chemical reaction between 2 reactants. A and B. Reaction occurs when both are present. When one reactant is used up, the reaction stops.

In this case, A is the acidic water, B is the alkaline shell grit. The shell grit dissolves in the water until the acid is used up, then the reaction stops.

Because the shell grit is solid, the remainder sits in the now neutral water until more acid is produced for it to react with.

I've dissolved shell grit in vinegar, so I'll get Mon to check the pH of that, too. (Although all I really wanted to do was make it go fizz )

ohhh and she's smart too

keep your fishy mitts off her you devo i was happier when she was doing it with the silk worms

Wot thread was that in again - has there been a retort?

Highest nitro feeding plants

Heather, thats the lines i was thinking on. You may already know, but there is a funky little equation for calcium carbonate in water, and its a two way reaction thats always in equilibrium. For example if there is alot of CO2 in the water forming carbonic acid the calcium carbonate dissolves in the water, if the CO2 is suddenly removed from the water (say by heavy airation) then it can tend to precipitate back outas a white powder.

VB didn't even think of the town water until you mentioned it. I looked up the water board info a few months back and there is a couple of burbs here that still use concrete pipes, hence the water to those lines get buffered to the extreme to prevent the concrete getting eaten away.

I wouldn't think that would be the case here.

RESULTS WERE as predicted b y the nerd fraternity here LOL

all mugs with varying amonts of shell grit returned a ph of around 7.5 this morn ing, while the control was around 7.2

So, i'm sure there's a minimum amount of grit to be effective, but it doesn't seem like there is an overdose level.

Next issue is, do i sift out the sand before putting it in the grow beds?

Okay test results so far:
B1 - PH risen to 6.6
B2 - PH around 7.6

C'mon Mon, get outta bed and check your vials...............yawn!

LOL, beat ya to it by a minute old man!!!!

I know about the trick of winding back the time before posting Mon - I just don't resort to dirty tactics :tongue10:

Results after 24 hours
B1 - 7.2 (from 6)
B2 - 7.6 and steady

if this remains constant then B1 should be around 7.6 tomorrow morning