Adding KHUP

[Peboy]

After adding khup I experience this cloud and wonder if it's good for the inhabitants and why its happening.

I only use RO water in this tank?

Thanks


Nate

 

[dw1305]

Hi all,
No, it definitely isn't anything to worry about.

After adding khup I experience this cloud and wonder if it's good for the inhabitants and why its happening.

It is probably calcium carbonate (CaCO3) coming out of solution. If you add the "KHup" with your macro/micro nutrients it maybe another sparingly soluble compound (like calcium, or iron, phosphate). I don't know exactly which carbonate compounds are in "KHup", but it is probably sodium (Na) & potassium (K) mix.

You usually get precipitation when you add a more soluble carbonate (like sodium bicarbonate (NaHCO3)) to a solution that is already saturated with (bi-carbonate) HCO3- ions. Calcium carbonate (and other divalent cations) are less soluble than monovalent cations.

Carbonates are strange compounds because they are insoluble in water, but soluble in weak acids. Carbon dioxide (CO2) is soluble in water, and a small proportion of that dissolved CO2 becomes carbonic acid (H2CO3) and this then causes a small proportion of the insoluble CaCO3 to solubilise as Ca++ and 2HCO3- ions.

The curious thing is that you are using RO, so you wouldn't expect the water to be saturated with calcium or carbonate ions, unless your rock is limestone?.

If you have hard tap water (often why people use RO) you can just add a small proportion of tap water (~10%) to the RO, you don't need the "KHup".

cheers Darrel

 

[Peboy]

Thanks Darrel,

Really awesome response totally appreciated!!!

I use RO water for the UG carpet, someone told me they grow better with RO water,

My tap water is already soft but I add salty bee shrimp minerals to buffer the RO water.

I found the UG stunted when using RO water so decided to revert back to tap water with a ph of 7.

I have just made the swap from RO to tap water and will monitor the UG.

Thanks again @de1305


Nate