Backyard Aquaponics
A place to discuss aquaponics

Hi everybody,

I need your help guys!! I've been running my system for a year now and I can't seem to get the pH down.

I give you some details more about the system to see if someone can help me.

System

- Outdoor
- Grow bed: 1.5 square meters with with expanded clay as substrate
- Fish tank + sump tank: 300 L with Vulcanic stone at the bottom
- 8 fish at the moment average size (about 8/10 cm each).

Current water values

Ph: 8
KH: 10
NO2: <0.01
NO3: 10
NH4: <0.05

I have been inserting a biological PH Down for hydroponics for a week now but it has not lowered the value at all. The KH, on the contrary, continues to rise every day.

Can anyone give me any ideas as to why this is happening and how to go about solving it?

Thanks a lot to everybody in advance,

Regina

Have you checked to see if your volcanic stone is alkaline?

KH of 10 will be holding it there for sure,but you didn't mention the GH.It could be the water you're putting in or something that's in the system like what Brian said.Do you have any wood touching the water?.

Try testing the water you're putting in & see if that's high on both GH & KH and maybe bring the PH down of your top up water first before you add it to the system.

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