KH & GH 12 with RO water?

[Gilles]

I re-filled my tank with RO water, and measured a KH of 3 the day after i filled the tank. Ideal you would say. Now, 2 weeks later i remeasured my tank water and it had a KH of 9 and GH of 12.

My tank has black gravel (100% calcium free) and Dennerle deponitmix professional. There are those white pallets in it, but i don't think they can boost the KH and GH that much in so little time can they?

My filter is an Eheim 2080 with both Eheim Substrat Pro and Eheim EHFIMECH.

Any tips are welcome!

 

[detlef]

Hi Gilles,

my first quess would be you are using kind of rocks which raise KH and GH (e.g. mini landscape)?

Regards, Detlef

 

[jonny_ftm]

I lived same bad expierience loosing many shrimps at waterchanges. It was calcareous stones I didn't test.

Get some 10% HCl and test your stones and black gravel. A 100% calcium free gravel doesn't exist except advertising claims. There always be some calcium, but how much?

A good test is to mix some of your gravel with RO in a glass, let it rest for a week and test water (close glass to avoid evaporation that will false the results

Deponit mix, I'm not sure about it, google "Deponit GH" and let us know please

 

[Gilles]

Well i have no rocks in my tank, it must be either the deponitmix or the gravel, will test it and let you guys know.