Backyard Aquaponics
A place to discuss aquaponics

now some of the members will know this, but some like me may not...

since starting this adventure , i have constantly had my water ph of around 8. and i have been reading the forums through and this is a similar problem.

recently i had redesigned my gb's and added another couple of beds, so i needed more gravel. i went to the local sand and gravel place and walked around grabbing a small hand full of stones from each type.. went home and placed the stones in a cup of water overnight to gauge the ph the next day...

some of the tests were higher in ph.. some the same... but 1 was lower... infact it had dropped the ph from 8.2 to 6 overnight... i have done this test a few more times and the results were similar..

i have now added that type of stone into my new gb and it has been working away for about 2 weeks.. the overall ph of my system is now 7.4..

i think there is a couple of rock doctor members..who might be able to explain this a little better..but to those who are having trouble getting their ph down... a quick visit to the sand and gravel shop and a testing the gravel may help..

Lots of things can cause variations in PH, however generally the PH in an AP system will drift downward towards acidic, due to the nitrification process.

Agree with the idea of testing gravel to check the PH effect however, be carefull with using any gravel that pushes the system to far towards acidic too early in its life. As the system ages you might find yourself struggling to keep the system at a suitable level (6-7)

It is usually pretty easy to get some limestone to use as buffer. The more common problem is people wind up using limestone as their media and the pH never comes down!!!!!!!

Any idea what kind of rock that gravel that brought the pH down is made of? Diatomite perhaps?

An inert media is usually the best choice and then the only buffering needed is to balance the bacterial action. However, most of us don't live in a perfect world and we must do our best to figure out how to make things balance well.

Good suggestion about testing the different media before buying!!!!!

Might have been a scoria...

Does scoria bring it down?!

We know maidenwell brings it (wayyyy) down.

Concrete apparently does NOT affect pH (or so C1 says).

Yep, diatomite is good for bringing it down...