• ARRSE have partnered with Armadillo Merino to bring you an ARRSE exclusive, generous discount offer on their full price range.
    To keep you warm with the best of Merino gear, visit www.armadillomerino.co.uk and use the code: NEWARRSE40 at the checkout to get 40% off!
    This superb deal has been generously offered to us by Armadillo Merino and is valid until midnight on the the 28th of February.

Liquid Soil pH test kits, what in them?

I need to test a big area of my soil for pH. The meter i have isnt reliable, and i dont find the use of indicator papers reliable either for this. Ive ordered a liquid based test kit, but it only does 15 samples.

Do any of you learned chaps know what the liquid/buffer power etc contained in these kits is? If i can find that out, then its almost certain i can get decent quantities of it at reasonable prices from a chemical supply house and save myself a few bob.

Im presuming its an indicator liquid and a pH buffer powder


You're really wanting to test the latest batch of peruvian marching powder aren't you?
I dont think it will be litmus per se, ive a feeling its more likely to be one or other of the various 'universal' indicators.

Actually, PA, its to help try and cure club root. Think my plots too small to be cost effective growing showbiz sherbert
All it is is litmus powder either added to liquid (distilled water) or impregnated in paper. You can buy it in bulk Litmus powder

You can buy it from any pharmaceutical supplier.
I think ordinary Litmus solution has too wide a range to be accurate, ie pH 1-14. For soil use it only needs to be between pH 5-8. The test kits all seem to give a green indication scale.

Ive discovered that the powder in the kit is barium sulphate, which is a flocculant. Its there to clarify the sample suspension to make the indicator colour more readily visible.

Nitrazine seems to have the required pH range, but im not sure how it indicates, i dont think ive ever had call to use it.
With Nitrazine the color changes as pH changes, giving a broad range of colors from yellow through blue. Nitrazine strips are commonly used to test the vaginal pH of expectant mothers. :thumright:

Latest Threads