HarvEv Mini Manual Units · New Vision Trust
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The Trust is growing.

Every reading on this page was taken by a teacher and pupils, in person, with their hands. This is what climate action looks like when it lives in a school.

5/5
Schools reporting
55
Total readings logged
18
Logbook entries
17 Jul
Most recent activity

Downshall Primary

3 units · Downshall
15 Jul
DOW_MIN_01 Downshall — Unit 1 (Basil)
🌱 Basil
Lead: FO
pH
7.7
EC
0.39 mS/cm
Water temp
23 °C
Reservoir
10 %
🍂 Plants reported as wilting
↳ 5 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
EC
Plants are getting hungry.
Add nutrient solution following the bottle instructions for your unit volume (~4 litres). Retest in 30 minutes. Recheck pH afterwards — feeding can shift it.
Why EC under 1.0 means there's not enough dissolved nutrient for healthy growth.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Reservoir
Top-up needed.
Add plain water before the next lesson, bringing level above 60%. Recheck pH and EC after — fresh water dilutes both.
Why Plants are drinking faster than expected. Lower water means stronger nutrient concentration.
Plant status
Plants wilting — investigate now.
Check the water level first — that's the most common cause. If reservoir is fine, listen for the pump (a soft hum should be audible). If the pump is silent or clicking, contact the Trust. Photograph the plants and any readings.
Why Wilting almost always means roots aren't getting water — either the reservoir ran dry or the pump stopped circulating.
The plants are thriving. They are ready for harvesting and will be harvested tomorrow.
Unit photo Unit photo Unit photo Unit photo
pH trend · last 8 readings
Logbook · last 5
15 Jul
Nutrients added · 15mls of nutrient added today as plants have started to germ
Nutrients and water was topped up after it was noticed that the plant was wilting. After the scienc…
29 Jun
Harvest taken · 1.5L of water added
After the basil was harvested, they were used in a science lesson about asexual (vegetative) reprod…
22 Jun
Class visit
The water temperature is within the normal range. The plants have grown significantly compared to l…
15 Jun
Water topped up
Water was slightly acidic. It will be measured again next week and action will be taken.
9 Jun
Other
The leaves look green and healthy.
DOW_MIN_02 Downshall — Unit 2 (Rocket)
🌱 Rocket
Lead: P-B
pH
0.83
EC
0.49 mS/cm
Water temp
24 °C
Reservoir
10 %
🌱 Plants reported as healthy
↳ 4 actions recommended show
pH
pH too acidic — act now.
Add 2–3ml of pH-up solution to the reservoir. Stir gently. Retest in 1 hour. Repeat once if still under 5.8. Don't add more than twice in a day.
Why Below 5.4, plants struggle to take in nitrogen and calcium. Leaves will start yellowing if left.
EC
Plants are getting hungry.
Add nutrient solution following the bottle instructions for your unit volume (~4 litres). Retest in 30 minutes. Recheck pH afterwards — feeding can shift it.
Why EC under 1.0 means there's not enough dissolved nutrient for healthy growth.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Reservoir
Top-up needed.
Add plain water before the next lesson, bringing level above 60%. Recheck pH and EC after — fresh water dilutes both.
Why Plants are drinking faster than expected. Lower water means stronger nutrient concentration.
Topped up the reservoir to 100% and have added alkali solution to the water and stirred. Noticed that some leaves look a little yellow which is in keeping with the advice given. Will harvest this week.
Unit photo
pH trend · last 6 readings
DOW_MIN_03 Downshall — Unit 3 (Mint & Lettice)
🌱 Mint & lettice
Lead: Mr M
pH
5.79
EC
1.1 mS/cm
Water temp
26 °C
Reservoir
60 %
🌿 Plants reported as thriving
↳ 2 actions recommended show
pH
Slightly acidic — keep an eye on it.
Plants are still okay, but watch over the next few days. If pH is still under 5.8 next week, add a small amount (2–3ml) of pH-up solution and retest after an hour.
Why When water gets too acidic, plants can't fully absorb their nutrients even if the EC reads correctly.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
The lettuce is ready to harvest
Unit photo
pH trend · last 6 readings
Logbook · last 2
9 Jul
Water topped up · Water topped up from 1.6 to 2.5L
23 Jun
Nutrients added · 15ml nutrients added

Elmhurst Primary

6 units · Elmhurst
2 Jul
ELM_MIN_01 Elmhurst — Unit 1 (SI / SEND)
🌱 Strawberry 🌱 Lettuce
Lead: SI
pH
8
EC
1.9 mS/cm
Water temp
27 °C
Reservoir
66 %
🌱 Plants reported as healthy
↳ 3 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
EC
A bit rich — dilute gently.
Top up the reservoir with plain (unfertilised) water. Stir, then retest. Often a 200–500ml top-up brings EC back into range.
Why EC creeps up over time as plants drink water faster than nutrients.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Corriander is doing well. Basil getting taller.
Added PH down and changed water to cool it down.
Unit photo
Logbook · last 1
19 Jun
Water topped up · Topped up to 3 litres
Strawberries are needing a lot of water
ELM_MIN_02 Elmhurst — Unit 2 (Teacher #1)
🌱 Basil 🌱 Lettuce 🌱 Coriander
Lead: AC-H
pH
7.7
EC
2.04 mS/cm
Water temp
21.6 °C
Reservoir
80 %
🌱 Plants reported as healthy
↳ 2 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
EC
A bit rich — dilute gently.
Top up the reservoir with plain (unfertilised) water. Stir, then retest. Often a 200–500ml top-up brings EC back into range.
Why EC creeps up over time as plants drink water faster than nutrients.
Two basil plants have not sprouted yet. Plant looks healthy but not much growth.
Added PH down solution. Topped up reservoir.
pH trend · last 4 readings
ELM_MIN_03 Elmhurst — Unit 3 (Teacher #2)
🌱 Strawberry
Lead: AC-H
pH
8.3
EC
0.49 mS/cm
Water temp
24.2 °C
Reservoir
95 %
🌿 Plants reported as thriving
↳ 3 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
EC
Plants are getting hungry.
Add nutrient solution following the bottle instructions for your unit volume (~4 litres). Retest in 30 minutes. Recheck pH afterwards — feeding can shift it.
Why EC under 1.0 means there's not enough dissolved nutrient for healthy growth.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
We have strawberries! At the moment they are white but we have spotted loads!
Unit photo Unit photo
pH trend · last 8 readings
Logbook · last 5
2 Jul
Water topped up · Topped up with cooler water
Temperature was high
2 Jul
Nutrients added · Added nutrients- 15ml
The strawberries were very low in nutrients.
25 Jun
Water topped up · Replaced all the water with fresh, cold water
During the heatwave the temperature reached 28.9 degrees! We replaced all the water with cool water.
19 Jun
Other · Added PH-down solution
PH levels were high
15 Jun
Other · Added PH down solution
PH level was 8 so added down solution.
ELM_MIN_04 Elmhurst — Unit 4 (Reception display)
🌱 Basil
Lead: SI
Awaiting first reading
ELM_MIN_05 Elmhurst — Unit 5 (Community giveaway #1)
🌱 Lettuce
Lead: SI
Awaiting first reading
ELM_MIN_06 Elmhurst — Unit 6 (Community giveaway #2)
🌱 Basil
Lead: SI
Awaiting first reading

Gallions Primary

2 units · Gallions
6 Jul
GAL_MIN_01 Gallions — Unit 1 (Strawberry)
🌱 Strawberry
Lead: BP
pH
10.4
EC
0 mS/cm
Water temp
26 °C
Reservoir
66 %
🌱 Plants reported as healthy
↳ 3 actions recommended show
pH
pH too alkaline — act now.
Add 2–3ml of pH-down solution to the reservoir. Stir gently. Retest in 1 hour. Repeat once if still above 6.8.
Why Above 7.5, several key nutrients become locked out. Plants will pale and stop growing.
EC
Plants are getting hungry.
Add nutrient solution following the bottle instructions for your unit volume (~4 litres). Retest in 30 minutes. Recheck pH afterwards — feeding can shift it.
Why EC under 1.0 means there's not enough dissolved nutrient for healthy growth.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Unit photo
GAL_MIN_02 Gallions — Unit 2 (Strawberry)
🌱 Strawberry
Lead: BP
pH
10.2
EC
0 mS/cm
Water temp
25.8 °C
Reservoir
95 %
🌱 Plants reported as healthy
↳ 3 actions recommended show
pH
pH too alkaline — act now.
Add 2–3ml of pH-down solution to the reservoir. Stir gently. Retest in 1 hour. Repeat once if still above 6.8.
Why Above 7.5, several key nutrients become locked out. Plants will pale and stop growing.
EC
Plants are getting hungry.
Add nutrient solution following the bottle instructions for your unit volume (~4 litres). Retest in 30 minutes. Recheck pH afterwards — feeding can shift it.
Why EC under 1.0 means there's not enough dissolved nutrient for healthy growth.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Plants have grown a lot in the last week.
Unit photo
pH trend · last 2 readings

Nelson Primary

2 units · Nelson
17 Jul
NEL_MIN_01 Nelson — Unit 1 (Basil)
🌱 Basil
Lead: WM
pH
8.4
EC
— mS/cm
Water temp
— °C
Reservoir
— %
🥀 Plants reported as stressed
↳ 2 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
Plant status
Plants stressed — check the water first.
Almost every plant problem starts with the reservoir. Check pH (5.8–6.8?), EC (1.0–1.8?), water temperature (17–22°C?), and water level (above 40%?). If all four are good, check the grow light is working and that the unit lid isn't blocking new growth. Photograph anything strange.
Why Stress is usually a sign of one or two readings drifting out of range, not a plant disease.
pH trend · last 8 readings
NEL_MIN_02 Nelson — Unit 2 (Basil)
🌱 Basil
Lead: WM
pH
4.3
EC
— mS/cm
Water temp
23 °C
Reservoir
80 %
🌰 Plants reported as germinating
↳ 3 actions recommended show
pH
Slightly acidic — keep an eye on it.
Plants are still okay, but watch over the next few days. If pH is still under 5.8 next week, add a small amount (2–3ml) of pH-up solution and retest after an hour.
Why When water gets too acidic, plants can't fully absorb their nutrients even if the EC reads correctly.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Plant status
Germinating — early days, be patient.
For the first 1–2 weeks after planting, this is exactly what should be happening. Most seeds (lettuce, basil, herbs) take 5–10 days to show their first green shoots. Keep checking the water level — fresh sponges drink quickly. No need to add nutrients yet; seeds carry their own food until first proper leaves. Photograph the pods so you can show pupils the change next week.
Why Plants in this phase look the same to the eye — sponges and empty baskets — but they are doing the most important work of their life cycle invisibly.
all of the seeds have sprouted

Vicarage Primary

2 units · Vicarage
29 Jun
VIC_MIN_01 Vicarage — Unit 1 (Mixed herbs)
🌱 Basil 🌱 Coriander 🌱 Lettuce
Lead: HZ
pH
7.9
EC
1.6 mS/cm
Water temp
25.5 °C
Reservoir
50 %
🌱 Plants reported as healthy
↳ 2 actions recommended show
pH
Edging alkaline — watchful.
Often this corrects itself as plants drink the water. If still above 6.8 next week, add a small amount (2–3ml) of pH-down solution and retest.
Why Plants prefer slightly acidic water. As pH rises, iron and phosphorus become harder to absorb.
Water temp
Water is getting warm.
Move the unit away from direct sun or radiators. After lessons, lift the lid for a few minutes to vent heat. If readings stay high, replace 1 litre with cooler fresh water.
Why Warm water holds less dissolved oxygen, which roots need to breathe.
Our lettace has grown lots however it is getting quite crowded in the unit. We will be making pizza next week to finish our project and enjoy our crops. The pH is to high however we do not have any pH down solution.
Unit photo Unit photo
pH trend · last 4 readings
Logbook · last 2
8 Jun
Class visit
Children visit the unit every morning to see the changes. There has been alot of growth over the we…
22 May
Nutrients added · 15ml a and b
We are growing basil and lettuce in class with reception children. The children are very excited to…
VIC_MIN_02 Vicarage — Unit 2 (Expansion)
🌱 Basil
Lead: HZ
pH
6.7
EC
1.8 mS/cm
Water temp
22 °C
Reservoir
80 %
🌱 Plants reported as healthy
Very healthy!
Unit photo
pH trend · last 4 readings