[Marmalade07]

I have a rio 180 very well planted. My ph is rising and I can't stop it. It's jumped from 7.0 to 8.5 in 6 days! Any ideas?
My kh - 3dkh
Gh - 2dkg
Oxygen - 5mg/l

How can my ph be 8.5 ?


Substrate is
Onyx sand bottom layer
Eco conpleat black middle layer
And ADA Amazonia soil.

I though it maybe the sand but seachem says its only increases the kh.

 

[AVN]

How new is this tank?

 

[Marmalade07]

Around 8 weeks

 

[OVT]

Is there any stones / decorations in the tank?
Also, gH is always > kH

 

[Diana]

Put some of the substrate in a glass with some tap water, nothing else and see what it does.

You can do water changes to keep it down, but it will keep creeping up if it is something in the tank.

GH and KH are not the same thing, and either can be higher or lower than the other.
GH tests for calcium and magnesium.
KH tests for carbonates.
In nature they are often found together, calcium carbonate and magnesium carbonate are limestone and many related minerals. Most of these dissolve pretty easily in water, so the water has more or less calcium or magnesium (depending on the parent rock) and carbonate.

However it is entirely possible to have any of those materials by themselves, or in combination with other things that are not tested by the regular aquarium tests.

Rising KH almost always makes the pH rise. Carbonates are a buffer that tends to raise the pH.

What is the tap water KH without the sand?

 

[Marmalade07]

Tap water KH is 0 - 1dkh

 

[GeToChKn]

How much Amazonia did you add? It should be lowering pH, but i think it's competing with your other soils. ADA is going to release humic and fluvic acids to lower pH and absorb kH and other things in the water as it has a high CEC. Eco-complete has a very high CEC and may be absorbing the things the ADA is releasing and not allowing it the drop the pH. I've seen Eco complete raise or change parameters and I know some people say it's inert and doesn't but I've seen too many people on here to say it has messed with their param's as well.

I think you have two competing substrates and I'm not sure how it's going to work out in the long run. It's hard though that you layered your substrates, in a 150 gal tank no less, so you probably spent a tonne of money on substrate that you can never really remove in an easy fashion without either mixing it all up or scrapping it all.

What are you using to test your pH with?

Lastly, do the substrate in a cup test. I was getting massive algae in a few of my tanks after them running perfect with nothing changing for so long. Checked nitrates, 40ppm. changed water, back to 40ppm, changed more water, more, more, still 40ppm. Took out a cup full of aquasoil, in a cup, fresh water, 24 hours later, 40ppm nitrates. Bought a new nitrate test, 40ppm. My soil had absorbed all the nitrates from the water, then had enough and started releasing it.