Backyard Aquaponics
A place to discuss aquaponics

Cool, so i was right?

You can see from B1 that the process is also gradual, which is nice to the fishies

There is one downside in aquaria, probably not as critical in AP. Follow me on this one.................

Ph drops, CaCO3 dissolves and buffers back up
Ph drops, more CaCo3 dissolves to buffer it back up.

As ph is always dropping due to nitrification, and the Carbonate is always dissolving to buffer it back up, you can end up with very hard water.

In an AP system i'm fairly sure that the plants will be taking up some of the KH and GH, but this will need to be assesed from someones system later on in the piece.

Monya, can ya really do that dirty trick? Cool.

wouldn't water replenishment due to evaporation etc assist in keeping those levels down also?

How has EB's systems gone

i was thinking that, but then i revised.

When the water evaporates all the dissolved solids increase in concentration, when you add water it dilutes them again but adds more becasue of the DS in the top up water.

Only way its going to come out is by water exchanges OR if the plants take them up, which i'm tipping they do.

Eb needs not test kits, he uses the force. (and is doing better than me!)

Wow, I love the science experiments. We're going to my parents place at the beach for Thanksgiving. I have an assignment for the kids: collect shells! Our tap water is 6.4 pH with very little buffering. I did purchase some crushed coral that is in the bottom of one of the grow beds, but if I need a little more oomph, I can use the shells.

Mon, late again for your results I see:

B1 up to 7.4-ish, both the same so on to next test.

Threw in 1 tablespoon for every 200litres in my water tank, it is used only for the garden (and fish tank) - PH level <=6, see how it goes, no stirring just a bit of convection currents to move the water

could have something to do with a baby Les!!

Excuses - hah! (didn't know about that until I finally got to the post) - accepted :sunny:

yeh got to give a bloke a break now and then eh!
He didn't do much only the fun stuff..Hehe

I retested the ph in the mugs today, all were at 8 . So I tested the water in the system again. Still at 7. I thought it was heading down, but it seemsto have settled there. I read what VB said about his being steady, and seeing as we used the same type of gravel medium, I thought I should re-check it. Then checked barra's preferred ph- it's 7! so am going to leave it as it is ATM, if it ain't broke....

Nothing appeared to be happening so increased to 1tblspn/100litres - rise to about 6.4 in 3 days

interesting... I am going to test ph weekly and see how it goes. Seems like the shell grit will buffer to 8 if you put shit loads in, so caqreful monitoring of ph after adding the shell grit would be important too.

I'll look it up, as i'm sure it desn't go that high. DOn't forget there can be other complex reactions going on, any time i've left my system water in a ph test tube for 3 days (i'm lazy) i come back to find it off the scale, around the 8.0 mark, where as when i actually do the test it was 7.0. Will confirm now.

Steve

OK, no simple answer.

As i suspected the CaCO3 reaction is highly dependant on the amount of dissolved CO2.

In the atmosphere what are we upto now >350ppm CO2 it stabilises at 8.5

in aqueous solutions depending on the CO2 it can be as low as 6.5 to 7.0

Would explain drifts in test left for a few days, a change in the CO2 levels most likely.

Please if you have a better understanding of chemisrty than me confirm or deny the above, i do the best i can with my sleep deprived brain

why does life have to be so complicated LOL

Saw your pics of the tree trimming, I'd of been holding my breath for sure. Show some updated pics of inside? Please please please.