Bluelab pH Pen
Bluelab pH Pen

Bluelab pH Pen

Availability: In Stock
Brand: BlueLab
Bluelab pH Pen — Portable pH & Temperature Meter for Hydroponic Nutrient SolutionThe Bluelab® pH Pen is...
$104.99
$136.56
$104.99
Subtotal: $104.99

Lead Time

this product ships in 1-3 business days

  • Seres
Description

Bluelab pH Pen — Portable pH & Temperature Meter for Hydroponic Nutrient Solution

The Bluelab® pH Pen is a compact, fully waterproof handheld pH and temperature meter designed for fast, accurate pH measurement in hydroponic nutrient solution and other liquid applications. Trusted by growers worldwide, the Bluelab pH Pen delivers reliable readings with automatic temperature compensation (ATC) — ensuring your pH measurements are accurate regardless of solution temperature — in a durable, pocket-sized form factor that goes wherever you do.

The pH Pen features a double-junction probe for improved resistance to contamination and longer probe life, a backlit LCD display for easy reading in low-light grow room conditions, a hold reading function to lock measurements before removing the pen from solution, and a successful calibration indicator to confirm accurate calibration. Temperature is selectable in °C or °F. Fully waterproof with an auto-off function to conserve battery life. Runs on a single AAA battery (included). Bluelab pH Probe KCl Storage Solution and pH 7 and pH 4 calibration solution sachets are included to get you started.

Specifications

  • Measures: pH and temperature
  • Range: 0.0–14.0 pH / 0–50°C (32–122°F)
  • Resolution: 0.1 pH / 1°C (1°F)
  • Accuracy @ 25°C: ±0.1 pH
  • Automatic temperature compensation (ATC)
  • Double-junction probe (not replaceable)
  • Fully waterproof with auto-off function
  • Battery: 1 × AAA alkaline (included)
  • Includes: KCl Storage Solution, pH 7 and pH 4 calibration sachets

Frequently Asked Questions

What does the Bluelab pH Pen measure and how accurate is it?

The Bluelab pH Pen measures pH and temperature of liquid solutions. It has a pH range of 0.0–14.0 with a resolution of 0.1 pH and an accuracy of ±0.1 pH at 25°C — sufficient for precise hydroponic nutrient management where target pH typically falls between 5.5 and 6.5. Automatic temperature compensation (ATC) adjusts the pH reading based on solution temperature, ensuring accuracy across the temperature range encountered in most grow room environments.

Does the Bluelab pH Pen need to be calibrated?

Yes. Like all pH meters, the Bluelab pH Pen requires regular calibration to maintain measurement accuracy. Calibration uses pH 7.0 (buffer) and pH 4.0 (slope) reference solutions — sachets of both are included with the pen. A successful calibration indicator is displayed on screen to confirm accurate calibration. Bluelab recommends calibrating the pH Pen at least once a week in active growing environments. Store the probe in the included KCl Storage Solution after each use to maintain probe hydration and extend its service life.

Is the probe on the Bluelab pH Pen replaceable?

No. The Bluelab pH Pen uses a built-in double-junction probe that is not replaceable. The double-junction design provides improved resistance to contamination compared to single-junction probes, extending the useful life of the pen. When the probe reaches the end of its service life — indicated by slow response times, drifting readings, or inability to calibrate — the entire pen will need to be replaced. For a pH meter with a replaceable probe, consider the Bluelab Combo Meter or Multimedia pH Meter.

Is the Bluelab pH Pen waterproof?

Yes. The Bluelab pH Pen is fully waterproof, making it suitable for use in wet grow room environments, greenhouses, and outdoor settings. The waterproof construction protects the electronics from accidental submersion, splashes, and the humid conditions typical of hydroponic operations. The auto-off function conserves battery life when the pen is not in use.

Where can I buy the Bluelab pH Pen?

The Bluelab pH Pen is available through Seres Ag, a professional hydroponic and CEA equipment supplier serving growers across the United States. Purchase directly at seresag.com. Seres Ag offers expert product support, competitive wholesale and retail pricing, and US-wide shipping. For bulk or wholesale inquiries, contact the Seres Ag team through the website.

Shipping & Returns
We ship daily from Monday through Friday, and shipments are processed within 24-48 hours of cleared payment.
Orders placed over the weekend are processed on the next business day.

Free Shipping

Specific Vendors offer free shipping over a certain amount. This will be automatically applied during checkout.

Orders over $10,000 before tax qualify for free shipping!

Free Shipping only applies to domestic US (lower 48 states -- sorry, Alaska & Hawaii) shipments.

Shipping Rates

Shipping rates are calculated during checkout based on the weight, dimensions, and destination of the ordered items. We do our best to calculate the exact cost.

Updated 5/1/2023:

Please note that due to the higher shipping costs and larger dimensions of some of our products, our shipping calculator may not always provide an accurate shipping estimate. In these cases, we will reach out to you with an updated shipping quote after you place your order. If you have any questions about shipping costs, please don't hesitate to contact us before placing your order. We apologize for any inconvenience and appreciate your understanding.

Seres reserves the right to notify you of any additional shipping charges. We partner with multiple vendors and locations, which can alter shipping rates. In addition, there are conditions out of our control (rural areas, fuel surcharge, multiple shipments). If this occurs, you will be contacted immediately and have the right to modify or cancel your order for a full refund. 

Address Change / Order Cancellation

If you need to change the shipping address, please get in touch with us at support@seresag.com or call 1-877-237-3754. 

Once the order is shipped, we will do our best to perform an address intercept. You will be charged an Intercept Fee imposed by the shipping carrier. This fee varies from each carrier. Please note not all shipping carriers will accept address intercept changes.

If an order is canceled in transit, you are solely responsible for all shipping charges incurred by the Shipping Carrier.

Shipping charges will not be refunded.

Tracking

Once an order has been shipped, we will send an email and text message on file with the tracking number. If your order is fulfilled from multiple vendors or locations, you will receive shipment confirmations with tracking for each shipment. 

In addition, you can check the status of your order through the order confirmation email or within your profile page under Track Order.

Freight (LTL)

Scheduled appointments deliver freight shipments. You are responsible for inspecting for damage incurred in transit and signing before the driver leaves. DO NOT accept the shipment if there is any damage. If your freight shipment arrives damaged, contact us immediately.

Once delivered, we cannot reimburse paid freight charges or refund products.

Some restrictions may apply; Hawaii and Alaska do not qualify for free shipping offers.

Damaged Shipment

It rarely happens, but once in a while, products are damaged during Shipping. Therefore, please scrutinize all shipments for damaged or missing items before signing for them (if required).

The shipping carrier is responsible for items damaged during Shipping, which will most often be UPS, FedEx, or USPS. 

If assistance is needed, please get in touch with us immediately. Seres cannot promise refunds or replacements if this is not done within 72 hours. 

By signing your name and accepting shipment for a Freight(LTL) order, you get no reimbursement of freight charges, order costs, or any other charges incurred.

Lead Times

Please note that there is up to a 7-day processing period for orders containing Hawthorne products.

Signature

Due to the valuable contents of many products we sell,  the carrier may need a signature upon delivery. Please understand that this is a measure our company took to ensure safe delivery and fraud protection.

Third-Party Carriers will attempt to deliver a signature-required order three times. 

Please follow up with the carrier for assistance if a missed-delivery note is received.

If assistance is needed, please get in touch with us, so we can help contact the carrier. 

Shipping costs will not be refunded for missed shipments.


Seres is not responsible for any missing, lost, or stolen items.
 

At this time, we do not ship to post office boxes or APO/FPO addresses.  

For more information, please read our Terms of Service.

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