Product description
Aptus Substrate Buffer Liquid 250 ml – liquid calcium buffer for a low substrate pH
Drain pH creeping down and want to correct it without reworking your whole feeding schedule? The 250 ml bottle is a small, affordable way to see how Aptus Substrate Buffer Liquid handles it in a tent or a handful of pots.
What it is
Substrate Buffer Liquid is a liquid pH corrector and buffer made of micronised calcium in suspension, with no chlorides, ballast salts or contaminants. The calcium raises a substrate pH that has dropped too low and then holds it more stable, while also giving your plants a steady supply of calcium. It is the liquid counterpart of Aptus Substrate Buffer Powder and works in soil, coco and other media.
How far 250 ml goes
The dose is 20 ml per 10 L of water (1:500). This bottle therefore makes about 125 L, or roughly twelve 10 L watering cans. For a small grow that is several corrective flushes.
Using it in a small set-up
Measure the pH of your runoff or substrate first. If it is too low, dilute 20 ml in a 10 L can of plain water and give it as a flush. Do not mix it with other products and do not pH-adjust this water. Not measuring? Then simply apply it once, about a month after planting. Check the drain again before the next application.
- Contents: 250 ml
- Composition: micronised calcium in liquid suspension
- Dosage: 20 ml per 10 L (1:500)


