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Getting the environmental factors right in your hydroponic grow space is absolutely vital for success. Too hot or too cold and your plants will suffer. If the humidity level is too high then fungal infections can take hold. Too dry and plant growth will slow. Our thermometers and hygrometers (humidity readers) will let you know when the air in your grow room is out of the correct range. We even stock an anemometer (or wind speed indicator) so you can measure exactly how well your extraction fan is working! We also stock light meters, infra-red meters, pH meters and nutrient strength meters - everything you need for a successful grow.

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Get Your Environment Right


During the daytime, or lights-on period, you need to be aiming for temperatures of around 25° C (around 77° Fahrenheit).

Aim for temperatures of around 18° C during dark hours.


Typical indoor plants need humidity levels that start high during the vegetative growth stages, getting lower as they progress towards harvest. When propagating cuttings, you'll need humidity levels of around 80% to nurse them through their most vulnerable stages and compensate for the lack of roots. In the later vegetative growth stages, plants thrive at around 70%. As they progress through the bloom stages, you'll need to ensure that moisture levels stay below 60% or you'll be at risk of encountering mildew and rot, which could cost you a big chunk of your crop.

A simple grow room humidity meter (hygrometer) is an invaluble tool, and the Agrolab is perfect for the job. It will provide information on both temperature and relative humidity.

Looking to Push Things Even Further?

If you want to get more in-depth, take a look at our blog on vapour pressure deficit. We stock an array of products that will assist you in tracking VPD, like the Dimlux Maxi Controller and Plant Camera, but you can dip your toe in the water with a bit of knowhow and an infrared thermometer.

Maintain Optimal Nutrients


pH levels are an indication of the acidity or alkalinity of a given substance. In hydroponics, the pH of your solution affects the availability of nutrients, which is why we generally aim for a sweet spot of around 5.8. If you're running organic feeds, aim for around 6.5. Note that these numbers can vary depending on the particular nutrient range, so make sure you consult the label or feed chart first. The Essentials pH Meter is a great pH tester that gets the job done for a very reasonable price.


EC, or electrical conductivity, gives you an insight into the levels of dissolved minerals in your feed. In short, the higher the EC, the more concentrated the nutrient is. The Bluelab Truncheon is one of the most popular EC meters out there; it's been a customer favourite for years, which is largely down to its accuracy and the fact that it's practically indestructible.

To see our full Grow Tools / Accessories range, click here.