Everything you need to know about the Pax Bellum A.R.I.D., Part3 - Operation

Everything you need to know about the Pax Bellum A.R.I.D., Part3 - Operation

How many hours should the reactor be on for?

Macro-algae needs to be acclimated to intense light just like corals do. When loading the ARID reactor for the first time with macro-algae start with as little as 4hrs of light. Unless you know the intensity of the light your algae came from start off with 4hrs of light. Raise the photoperiod by 1 to 2hrs a week until reaching a maximum of 16hrs of light. If you find PO4 levels dropping below 0.02ppm reduce the number of hours the ARID lights are on until PO4 stabilizes around .02-.05ppm, or alternately buy more organisms and feed your aquarium more.

Do not run the ARID constantly with the lights on. Algae needs rest, and the recommended off cycle is 8hrs minimum. Running 24/7 will also negate the pH and oxygen stability of running a reverse daylight cycle.


How should I start and maintain the macro-algae growth?

We recommend starting with Chaetomorpha species of macro-algae in the beginning. When you become experience with how the ARID works by all means please experiment with other macro-algae. We will be very interested to hear your results. Until then, we have found Chaetomorpha is the easiest, fastest and most versatile species to grow.

Remove the light assembly by grasping the cool heat sink and pull and twist straight up. Place the light to the side in a safe place away from water or where it may be stepped on, or dropped. Open the lid of your reactor and lift the lid and armature assembly up and out of the chamber. The armature is comprised of the perforated discs (diffuser discs), spiral tube stretching between the discs, the rubber retainer rings and the light tube.

Start your reactor with at least 2-3 large handfuls of Chaetomorpha algae in each open segment of the Armature.  Make sure the algae is evenly spread around the light tube. Use the spiral tube to wrap around bundles of algae to help retain the mass. Space the bundles to expose the algae evenly to light along the vertical axis of the light tube. Load the armature back into the chamber, fasten the lid, replace the light assembly into the light tube, and attach your water supply, and return hoses. The water inlet port is on the base of your reactor. The outlet port is on the lid. Turn the supply of water to the reactor on. Use the recommended flow for your model ARID. This information can be found in your models quick start guide.

From day one start dosing the Iron + Manganese solution that came with your ARID reactor. This should be dosed at a rate of 1drop per 100L (26.4 US gallons) daily. These elements are difficult to test for but necessary for algae growth. These elements also tend to precipitate out of seawater rapidly and should be dosed daily to ensure they are present. 

The ARID is capable of targeting specific nutrient(s) for export by growing macro-algae. In the reef aquarium the main concern is balancing the nutrients N:P:K:C, with the goal of limiting phosphate (P). Usually never in short supply, Potassium (K) and carbon (C) are not usually dosed. However, Nitrogen (N) can become depleted by the growth of algae, causing its growth to stall. To keep the algae growing, the aquarist should dose the, “Nitrogen+Molybdenum” solution that that came with your ARID system, at a rate to maintaining the NO3 level at a minimum of 20:1 and ideally a 100:1 ratio to phosphate (example; 3ppm NO3 to 0.03ppm PO4). This will allow the Chaetomorpha or macro-algae of choice to continue to grow until phosphate levels are depleted.

The “Nitrogen + Molybdenum” solution should be dosed as needed. 1ml of this solution will raise 100L (26.4 us gallons) by approximately 0.5ppm NO3. Not all of the nitrogen is in the form of nitrate, for accurate nitrate readings, tests should be performed at least 6hrs after dosing. Do not raise your nitrate levels by more than 1ppm per day. Try to dose your system at the same time your ARID lights come on to maximize uptake by the algae.  In the first month your ARID reactor should be opened weekly and growth checked. Shut down the feed pump and light and disconnect the effluent connection located at the top of the unit. This allows the unit to drain down. Remove the lid and light assembly and empty the Chaetomorpha into a 5 gallon bucket, add to this enough tank water to submerge the algae. If your chamber was full of Chaetomorpha you can harvest up to 1/3 of the mass. The remaining algae should be rinsed in the bucket of aquarium water by vigorously plunging the algae up and down through the water surface to dislodge any detritus and biofilm. Discard the biofilm laden water remaining in the bucket. Remove the algae from the bucket and stretch and expand the mass so that it fills the armature again. Exactly like when you started your ARID for the first time, make use of the spiral wrap to hold and distribute the algae evenly along the length of the light tube. This will maximize light coverage, and get your algae growth off to a good start again.  Growth may slow after the first month as target nutrient(s) become depleted. At this point, the reactor can be serviced every other week. Even if growth is not sufficient to harvest, the Chaetomorpha should be rinsed, stretched, and placed back into the reactor. Remember the biofilm is a nutrient export mechanism and rinsing keeps the algae free of detritus and healthy.  For more information on balancing nutrient ratios and maximizing your Chaetomorpha’s growth potential please refer to our “white paper”.

Does the ARID need to be placed in my sump?                                                                                                                                                               All ARID models are watertight and were designed to operate outside the sump for easy maintenance. The ARID models can stand or hang in the case of the N18 on the rim of a sump. We don’t recommend placing  them in a sump where they could be knocked over causing  the electrical connection to come in contact with water. Please be safe around electricity and water, always use GFCI sockets and place drip loops on all power cords. 

What is the purpose of the Calcium Injection Assembly?

The “Calcium Injection Assembly” allows the calcium reactor effluent to pass through the macro-algae in the ARID reactor where it is stripped of a large portion of excess CO2 and PO4 before entering the rest of the aquarium system. The assembly gets rid of the need for a dedicated supply pump for the calcium reactor.  Instead, the ARID supply pump is used to send water to the calcium reactor.


How does the Calcium Injection Assembly work?

The “Calcium Injection Assembly” attaches to the ARID intake port. The assembly consists of a manifold with a high pressure and a low pressure side. This pressure differential is accomplished by having a user configurable restrictor placed between the two ports. The “restriction discs”, are washers with varied center holes that can be swapped out to tune the assembly to the ARID supply pump. The high pressure side port, found closest to the ARID supply pump sends water to the calcium reactor. The low pressure side port, found closest to the ARID inlet accepts effluent from the calcium reactor. Between the low pressure port and the calcium reactor is placed a drip counter so the flow rate of the calcium reactor effluent can be monitored as it enters the ARID.




How can I order replacement parts or additional supplements?

Please email use directly at sales@pax-bellum.com or by phone at 802-293-6213. You can also purchase any of our products by contact one of our distributors;



Do I need the optional quick disconnect fittings?

If you have purchased an ARID C-series reactor your reactor came with quick disconnects, you do not need to buy any. If you purchased an ARID N-series reactor the quick disconnects are offered as an option. This was done to keep the price of the reactors down. Being smaller reactors than the C-series they can easily be moved around and don't necessarily need quick disconnects if the tubing leading from the lid to the sump or aquarium is short. If you have plumbed your N-series reactor into a manifold, or the tube leading out of the ARID to your system is long the quick disconnects make routing maintenance much faster, easier, and more likely to be done regularly.  We do recommend this part.

What other filtration equipment does the ARID replace or isn’t compatible with?

The ARID displaces the need for; GFO, Chemical absorbents, bio-pellet reactors, Zeo-vit, carbon dosing, de-nitrifiers, lanthanum dosing, refugiums (used as nutrient export), Algae Turf Scrubbers, and even Protein Skimmers.

We do not recommend the use of GFO, carbon dosing, bio-pellet reactors, Zeo-vit, de-nitrifiers, kalkwasser reactors, Lanthanum Chloride dosing, refugiums (used as nutrient export), Algae Turf Scrubbers or ozone in conjunction with the ARID system. Running these systems with the ARID can, and will cause problems. Skimmers and activated carbon are fine to use with the ARID system but not necessarily needed. UV sterilizers have been attached to the input port of ARID reactors and shown no negative effects.


The ARID macro-algae reactor system is patented.  What does that mean?

“A patent for an invention is the grant of a property right to the inventor. Patents are granted for new, useful and non-obvious inventions for a period of 20 years from the filing date of a patent application, and provide the right to exclude others from exploiting the invention during that period.  U.S. patents are issued by the United States Patent and Trademark Office.  Generally, the term of a new patent is 20 years from the date on which the application for the patent was filed in the United States or, in special cases, from the date an earlier related application was filed, subject to the payment of maintenance fees.  The right conferred by the patent grant is "the right to exclude others from making, using, offering for sale, or selling" the invention in the United States or "importing" the invention into the United States for a limited time in exchange for public disclosure of the invention when the patent is granted.  Patents are territorial, meaning that one must apply for patent protection in each country where protection is sought.  In other words, U.S. patent grants are effective only within the United States, U.S. territories, and U.S. possessions. The USPTO Inventors Assistance Center (IAC) provides patent information and services to the public. The IAC is staffed by former Supervisory Patent Examiners and experienced Primary Examiners who answer general questions concerning patent examining policy and procedure. The IAC can be reached by telephone at (800) 786-9199.”  https://www.stopfakes.gov/article?id=What-is-a-Patent

The ARID macro-algae reactor is a patented bioreactor in the USA and pending internationally under the following numbers:

U.S. Patents: 9,388,372; 9,695,389

International patents pending:  WO 2016/073901



Source: Pax Bellum Inc.