Help needed from Chile!

[Marko]

Hi everybody!

We are two Chileans that are trying to get our first aquaponic system running in Santiago and we have so much questions!

However, one of them is the most urgent and we humbly request the community’s assistance and guidance.

We have built a traditional IBC CHOP 2 system, with one full IBC for the fishes (1000 lts), three IBC beds and a sump tank. We have attached a picture so you can see more clearly what we are talking about.

Our problem is that we haven’t been able to find a suitable media for our system. Hydroton and expanded shale do not exist here or have prices we can’t afford, volcanic rock may be an option since there are volcanoes in the south of the country, but availability in our area is a problem and we haven’t found suitable vendors (only Little bags for the grills).

So, we are trying with gravel, but we can’t seem to find anything that keeps the ph of the water at aceptable levels. We have been testing experimentally with different sources using destilled water and electronic ph meters (calibrated) and none of the samples tested have been lower than ph 8.

Our question is: Is it possible to use this medium and expect the cicling process or artificial ajustments with HCL to stabilize the ph of the system at an aceptable level? Or should we keep looking?

Thanks in advance!