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Isol8 Rb

Rubidium Solution: 5,000 ppm

C8R 3D Isol8 Rb 60 mL.bmp


  • Rubidium


5,000 ppm


  • Active Components: Rubidium bromide, anhydrous, USP.

Basic Application

  • 1 drop (0.05 mL) per 0.552 gallons (2.089 L), or 1 mL per 11.040 gallons (41.786 L), provides NSW [Rb].

  • 1 mL per 26.4 gallons (100 L) increases [Rb] by 0.05 ppm.

  • Reference Standard [Se]:

    • 0.1197 ppm (S=35.0)​

    • 0.1362 ppm (S=40.0)

  • In established systems, increase [Rb] up to 5% of existing ionic value daily, until desired value or reference standard is reached.

Purchasing Options

Reef Blueprint (packaged in sizes suited to systems ≤500 gallons)

Captiv8 Aquaculture (larger systems, commercial, academic, research, zoological)


Application of Isol8 Rb provides rubidium, taken up in a similar fashion to potassium, and potentially incorporated into biopigments appearing deep-red to purple, the degree to which this occurs being at least partly related to the predominant accessible form of dissolved inorganic nitrogen.  Anecdotal accounts of shifts in coloration of corallimorpharians with consistent Rb supplementation may be a result of this process.


Rb must not be overdosed.  A reliable ICP analysis (performed by a service provider who has the ability to accurately determine [Rb+]) must be performed prior to commencement of Rb supplementation, to ensure that dosing is consistent with existing system [Rb+].  Thereafter, ICP analysis performed on at least a monthly frequency will provide rate of system Rb uptake, enabling modification of Rb dosing as necessary.

Note that the use of zeolite intended to curtail ammonium content in recirculating marine ecosystems will also remove potassium and rubidium.

Recommended is diluting an appropriate volume of this solution into a larger volume of purified water (with a purity of at least 98%), and applying this diluted solution to the system with an automated dosing system. Dosing frequency is directly proportional to stability of ionic concentrations and, resultantly, continuous cohort biomass growth.  A 1 - 10 s drip interval provides adequate ionic stability, and is recommended.

If no automated dosing system is available, then apply solution manually each day. Dosing frequency is directly proportional to stability of ionic concentrations and, resultantly, continuous cohort biomass growth.  Dosage volume per 24 h is divided by the dosing frequency*.

It is not recommended that this formulation be dosed fewer than four times weekly.

Reference Standards: 1 mL Isol8 Rb diluted in 26.4 gal. (100 L) water yields 50 μg/L increase of [Rb].

To calculate required solution volume for known parameter differential:

  1. Multiply net water volume (L) by actual [Rb] (ppm).

  2. Multiply net water volume (L) by desired [Rb] (ppm).

  3. Subtract product of Step 1 from product of Step 2.

  4. Divide difference of Step 3 by 0.50.  Answer is drops sol’n required to achieve desired [Rb] in situ.

Recommended: Do not increase parameter concentration by more than 5% per 24 h period in systems with existing cohorts.  Aside from emergencies (e.g. excessive nutrient content in an active system, greatly depressed or excessive salinity, etc.), gradual changes in water composition are generally tolerated better by aquatic organisms than are rapid changes.

*Example: If dosage volume per 24 h = 1 mL and dosing frequency = 4, then dose 0.25 mL per event.

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Notice: It is not possible to eliminate all risks associated with the use, handling, or storage of this product. Ineffectiveness, injury to crops and/or livestock, or other unintended consequences may result due to factors outside the control of Captiv8 Aquaculture or the seller. Buyer or user shall assume all such risks. For details, go to Terms and Conditions. Consult SDS before use.


Disclaimer: Captiv8 Aquaculture warrants that this product conforms to the description, and is reasonably fit for the purposes described, on its label. In no event shall Captiv8 Aquaculture or the seller be held liable for any incidental, consequential, or special damages, loss, or injury, including, without limiting, lost profits, resulting from the use or handling of this product. The exclusive remedy of the buyer or user for all claims shall be the return of the purchase price of this product. Express and implied warranties are disclaimed. Captiv8 Aquaculture does not authorize any agent or representative to make any other warranty, guarantee, or representation concerning this product.

For sale by Captiv8 Aquaculture and its authorized dealers, only.

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