Great Aquariums Start Here
Live Chat Support
    Free Shipping On $75+
  • FREE Shipping On $75+
  • 14-Day Low Price Guarantee
  • Low Price Guarantee
  • Same Day Shipping
  • Same Day Shipping
FREE Shipping on
Orders Over $75
Standard ground shipping (1-7 business days) starts at a low $4.99 and most orders over $75 ship FREE. Learn More
If you find a product we sell for a lower price at another online store, we will match their price to ensure you always pay the lowest amount when you shop with us. Learn More
Same Day Shipping
We promise to ship your order as fast as humanly possible. In fact, 99% of orders placed before 2 pm EST ship the same day! Learn More
Home » Saltwater Aquarium Supplies  » Testing Equipment  » Monitors & Controllers  » Multi Item Monitors & Controllers  » Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe

Average Rating 4 28
Write A Review
Product Review
We value your opinion & experience
Thank you for taking the time to review our products!

This is a Product Review for: Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe
Name to display on the review:
Location (ex: Anaheim, CA):
Your experience level:
How would you rate this product?
Review Title:
Write your review:
(Please focus on product quality and performance)
LOW STOCK ALERT: Only 8 left—order now!
In Stock: Order by 2PM EST for same-day shipping (M-F)
Item #:
Notify Me
Just enter your email address below and we'll let you know when the product you are looking for becomes available!

Item Code:
Your Email:
Add to Cart or Notify Me
This item is temporarily unavailable but will be back in stock soon.

Item #
Click the Add To Cart button below if you'd like to reserve this item today. Any other items included in your order will be immediately processed and shipped. We will ship this item separately as soon as it arrives. We will not charge you for this item until it ships and you will incur no additional shipping charges.
Enter your email address in the field below and click the Notify Me button if you'd like us to send you an email when this item becomes available. Although you will be immediately notified when we have stock on hand, we will not reserve any units for you; you must return to our website and place an order.

+ Add to Wishlist
Add to Wishlist
Select Wish List:
Comments (up to 200 characters):
Quantity Desired:
Quantity Received:
Qualifies for Free Shipping!
FREE Shipping Promo offers FREE standard ground shipping via UPS on orders of $75 or more for orders containing non-overweight or oversize items (orders which do not qualify for our FREE shipping promotion will still be shipped at a discounted rate).

Terms and Exclusions:
  • Offer valid only on orders shipping within the contiguous United States. Orders shipping to Alaska, Hawaii, Puerto Rico, Guam or other US Territories do not qualify for this promotion.

  • This promotion does not apply to items requiring expedited shipping, such as refrigerated products, frozen products or live rock.

  •'s FREE shipping promotion does not include products sent in oversized or particularly heavy boxes. This may include but is not limited to aquariums, canopies, chillers, external water pumps, metal halide magnetic ballasts, stands and substrate/sand. These items may be subject to additional shipping handling charges. Should shipping surcharges apply, they will be noted on individual product pages and / or displayed during check-out. We will, however, pay a portion of the shipping charges for these orders.

  • Shipping surcharges, such as special handling are NOT covered under the FREE shipping promotion.

  • Shipping charges for returned merchandise is non-refundable. Please read's Return PolicyPolicy for more information.

  • Price matched (Low Price Guarantee) or discounted orders do NOT qualify for our free shipping promotion.
If you find a product we sell for a lower price at another online store, we will match their price to ensure you always pay the lowest amount when you shop with us.

Enter the price, shipping cost and website address where you found the lower price. Then click the "Add to Cart" button. We will review the lower price while processing your order and make any necessary reductions before your order ships. Some restrictions apply. See Terms & Conditions.
Shipping Cost*
Competitor's Website*
*Required information
Marine Depot 60-day Returns
At Marine Depot, we stand behind our products. That is why we offer a 60-day return period: one of the best in the industry! Learn More Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe Information

Product Manuals & Documentation

We have teamed up with Digital Aquatics to bring you the best priced aquarium controller package available on the market today. Our Exclusive Digital Aquatics ReefKeeper Lite Package includes the ReefReeper Lite Basic Aquarium Controller, an RKM SLX Module and a FREE Digital Aquatics pH probe.

Package contents:
  • 1 x RKL Head Unit
  • 1 x PC4 - Power Controller 4
  • 1 x SLX (pH, pH/ORP, temp, and 2 x switch inputs)
  • 1 x Digital Aquatics iTemp Temperature Probe
  • 1 x (FREE) DA pH probe
  • 1 x SID - System Interface Device
  • 1 x Programming Coupler
  • 6 x Mounting screws
ReefKeeper Lite Preliminary Product Information
  • Expandable - up to 4 modules!
  • pH, ORP, and switch inputs (w/ optional SLX)
  • 16 timers / 16 alarms
  • Audible / Visual alarms
  • Wavemaker
  • Dual Stage Temperature Controller
  • Moonlight Controller (w/optional MLC)
  • Light Controller
  • Pump Controller

Manufacturer Info

Digital Aquatics Aquarium Supplies
Digital Aquatics was founded in 2004 and has quickly become the most recognized name in aquarium automation. Since the company debuted the original ReefKeeper 1 (now known as the RK1) in 2004, they have gone on to create some of the most flexible, innovative and cost effective aquarium controllers on the market. The revolutionary ReefKeeper Elite (RKE) was unveiled in 2008 and the affordable ReefKeeper Lite (RKL) came out shortly thereafter to appeal to more budget-conscience aquarium hobbyists. In 2010, Digital Aquatics released a reptile version, the HerpKeeper, as well as the aptly named PondKeeper. ReefKeeper controllers simplify aquarium keeping duties by monitoring and controlling a variety of water parameters and equipment including but not limited to lighting, water flow, heating, cooling, pH and ORP. Exclusive ReefKeeper Lite + SLX Expansion Unit w/ FREE pH Probe Reviews

Average Rating
(28 reviews)
Sort Reviews By:
of 3

Digital Aquatics-Reef Keeper

Reviewers Rating Unsatisfactory

Posted: 7/15/2015 from Houston, TX UNITED STATES
1.0 5
Experience Level: Intermediate

Comments: Digital Aquatics gets a thumb down from me. I have called them and sent them email. The Support department does not answer their phones and they do not return reply to emails. Reef Keeper does not save you money as I was hoping for. The PC4 can only take two cords for your lights and when you have multiple lights that have two cords each you have to end up buying multiple PC4's to accommodate your light systems. So don't waste your money on this system if you have multiple lights that have two cords each. Unless you are rich with very deep pockets lots of money in them.

Did you find this review helpful? Yes No


Reviewers Rating Excellent!

Posted: 6/20/2015 from Athens, OH UNITED STATES
5.0 5
Experience Level: Expert

Comments: This is a very good controller, as long as you don't need all the bells & whistles. Does everything that a I need for it to do! Apex is very nice, but if you just need to control a few things, this is way cheaper & will do all you need for it to do.

Did you find this review helpful? Yes No

Very nice starter controller

Reviewers Rating Great

Posted: 6/12/2015 from NY
4.0 5
Experience Level: Beginner

Comments: This is a great starter and upgradable control unit, and can't beat the price. I have been using the Basic version for many months and use it for: power heads/ wavemaker, heater, auto top off pump with dual float switches, pH + temp (comes with the unit), refugium light, main pumps. I did have to get a second power strip (PC4) for the main pumps as there are only 4 outlets on the strip, and only 2 of the 4 have sufficient amperage to handle pumps. The main reason I deducted one star is that every now and again my pH reading shows as "error". Originally I thought it was a probe issue, so I called DA tech support. They were extremely friendly and helpful. They gave me some "to-do's" and said if it doesn't work to let them know and they'd send a new probe right away. I actually found that it wasn't the probe at all but the SK1 unit. I think the issue is electrical interference from the jumble of wires I have for all my equipment fitting into a tight space, but I just need to disconnect the SK1 unit and plug it back in and it works again. My next upgrade will be the NET module to unlock the full potential of this controller.

1 of 1 People found this review helpful, did you? Yes No

Digital Aquatics Exclusive RFK

Reviewers Rating Great

Posted: 7/26/2014 from MORENO VALLEY, CA UNITED STATE
4.0 5
Experience Level: Intermediate

Comments: Price wise an excellent product, easy to setup, basically plug and play. Computer interface may need to be revamped if they want to stay competitive with Neptune. Great for smaller tanks. But overall, with temp and PH probe for $200 and your not hanged up on getting emails or using your computer to set up. I would recommend it. It's a entry level maybe border line novice controller.

1 of 1 People found this review helpful, did you? Yes No

Great Product for the Money!

Reviewers Rating Excellent!

Posted: 7/13/2014 from DENVER, CO UNITED STATES
5.0 5
Experience Level: Expert

Comments: I should have bought this a long time ago. I have a chiller that has a built in temperature control that stopped sensing the temperature and was not operating properly. This product was the best choice to control the chiller. On top of that I now can monitor Ph. Another feature is alarm setting. I have set up a high and low temp, also a high and low Ph. It can also be expanded for extras like ORP sensor, lighting control, pump control. For the cost this was a great buy.

1 of 1 People found this review helpful, did you? Yes No

awsome product

Reviewers Rating Excellent!

Posted: 1/23/2014 from Sioux Falls, SD UNITED STATES
4.5 5
Experience Level: Intermediate

Comments: I searched the web and looked at prices and reviews. I found this reef keeper $80.00 less then competitor and the reviews were great. I like it a lot and have had it up and running a week now. time will tell and if it dosnt hold up to my expectations ill revisit this review of mine and say so. id give it a 5 if the instructions were more can get the instructions by going to web sight company offers you on quick guide in box but you have to navigate around a bit. I slao like that ph probe is calibrated right out of the box, one last thing to deal with in the moment.

Did you find this review helpful? Yes No

Great basic controller

Reviewers Rating Excellent!

Posted: 7/5/2013 from STONINGTON, CT UNITED STATES
5.0 5
Experience Level: Intermediate

Comments: For a controller with pH probe, temp probe, and readily expandable to ORP and auto top off this unit is a bargain. Programming with the RKL's two screen display is actually well thought out and intuitive. I did not have to use the PC interface cable to get it setup at all. I have this unit on an 8 gallon nano FOWLR I have set up at work. This is running the heater, chiller (Nova Tec IceProbe), LED lighting, and powerhead/pump. Temperature stays between 75 and 77 degrees regardless of office temp. We had a severe AC failure resulting in office temps in excess of 85 degrees for days. Tank never got above 77.3 degrees. If you need your controller to connect to the internet/home network, then this isn't the controller for you. The Neptune Apex has NET features built in and a great user interface via software. This DA unit beats the Neptune hands down on interface without a PC. The Apex is virtually unusable without the PC. I programmed the DA without ever opening the manual, it really is that simple. The SL1 has so many features that it really does make up for the lack of a robust PC interface...A and B switch ports for auto top off (just add floats), ORP port, it has a plethora of features. This is the perfect solution for my small 'work' tank, and great for someone who wants all the bells and whistles without breaking the bank.

1 of 1 People found this review helpful, did you? Yes No

great product

Reviewers Rating Great

Posted: 3/10/2013 from SAINT PETERSBURG, FL UNITED ST
4.0 5
Experience Level: Expert

Comments: This is an awesome product! Well worth the price! Makes everything so much simpler. Not hard at all to install. The only thing I gave it 4 stars is because the reefkeeper elite has more standby modes. Which I would like more of. Ya know, one for feeding, one for water changes , even one for just pump maintenance. Nothing bad though. It's still an amazing product.

0 of 1 People found this review helpful, did you? Yes No

Run away!

Reviewers Rating Unsatisfactory

Posted: 2/20/2013 from CANYON COUNTRY, CA UNITED STAT
0.5 5
Experience Level: Expert

Comments: Overall the unit feels very cheaply made. Programming can be confusing. The outlets on the PC 4 don't make any sense. 1 and 4 are rated for 8 amps while 2 and 3 are only 3! Why?? Next, the relay switches dont work properly. You can only put pumps on a wave maker on outlet 1 and 4. If you put something with a low power draw on outlet 2 and 3, like a toms aqua lifter dosing pump, it gets stuck on due to the relays!!! Almost DESTROYED my tank. Just Doesn't make sense. Take your money and RUN!

7 of 9 People found this review helpful, did you? Yes No

Was great..

Reviewers Rating Average

Posted: 2/4/2013 from LOWELL, MA UNITED STATES
2.5 5
Experience Level: Intermediate

Comments: It was working great... until my Temp probe started going crazy and PH probe had to be replace within 3 months of use now my display date/time doesnt work at all. Last firmware update for this module was 2011 or 2010... GG. Was wondering why alot of people were starting to sell these on the forum with part of the package missing.

3 of 5 People found this review helpful, did you? Yes No

of 3
WIN CORAL FRAG RACKS! Sign up for hot deals, helpful videos and a chance to win 3 x ReefRacks for your corals!