When to buffer ph and with what

[Mantis]

The PH in my little system is down to 6.4 and has been coming down steadily from the 7.4 that it started at.
Should I put some buffering material in the beds yet and what would be good to use.
I dont actually want to raise the ph but dont want it to go any lower

[Murray]

Buffer when necessary is the go.....you could add a small amount of hydrated lime. Take note of how much you use and test the next day to see how much the pH has moved if at all.
In the morning I will look up my notes and give you some numbers per ltr for buffering.

[MalcolmC]

I recently used one handful of hydrated lime in 3500 litres and my Ph went from IIRC 6.0 to 8.4 :frown:

If I were doing it again I would use about 1 teaspoon per 1000 litres and, as Murray says, test it daily.

Mal

[Mantis]

I remember reading that M, not good eh :frown:
My system is only 500L so its only going to take small amounts of lime or whatever to keep it in the mid 6's range
More to learn :)

[RupertofOZ]

As you don't want to move the pH... just hold it... then add some shellgrit to the growbeds, or sump... under the water inlets....

pH of 6.4... is actually about perfect IMO....

[Murray]

3 tablespoons per 1000 ltrs.
Yes, a stocking with shell grit in it does help that is for sure.

[David McP]

I have been using oyster shells in a drum in the return line from sump to fish tank and the PH has stayed at 6.2 for more than 12mts In my latest systems I let PH drift down to PH 6.2-6.5 then add oyster shells and PH remains constant Seams as the system leached just enough calcium from shells Shellgrit or similar would probably do same

[Mantis]

I have been using oyster shells in a drum in the return line from sump to fish tank and the PH has stayed at 6.2 for more than 12mts In my latest systems I let PH drift down to PH 6.2-6.5 then add oyster shells and PH remains constant Seams as the system leached just enough calcium from shells Shellgrit or similar would probably do same

Thanks guys, and Davids idea sounds good. SHMBO is away for the week and a dozen oysters will make a nice starter tonight for dinner, (she hates them).
I will crush the shells and put them in stockings under the GB returns

Cheers :)

[Shane]

Thanks guys, and Davids idea sounds good. SHMBO is away for the week and a dozen oysters will make a nice starter tonight for dinner, (she hates them).
I will crush the shells and put them in stockings under the GB returns

Cheers :)

I'll be interested to see how you go Mantis,
I've got a dozen oyster shells buried in each GB in the maximus system.....yet I find I still have to buffer the system occasionally.

Cheers.

[RupertofOZ]

Oyster shells a very hard... and breakdown very slowly... shellgrit, being already ground, releases it's Calcium faster (relatively)...

Lots of shells in a drum.. like a trickle filter... is a good long term solution...

[Mantis]

Well it looks like a mixture of crushed oyster shells, (just have to get some now), and some shell grit, which the chooks probably need as well. :)

[RupertofOZ]

Shell grit would be sufficient on it's own...

[Mantis]

PH test tonight was yellow :eek:
So, a bag of shell grit under two of the growbed outlets

[fishfood]

In 5000 litres i put 3 table spoons of lime in about once a month

[Mantis]

I will be happy if I can keep it above 6, so the shell grit in my little 500L system should do it.
I will see how it goes for a while , but lime is an option for sure

[RupertofOZ]

Lime, particularly "slaked lime"... has an immediate pH buffering affect...

Whereas the shellgrit is a slower, self regulating, long term buffering agent...