• Provides temporary alkalinity and helps maintain pH within the desired range when used as directed.

• Adds no conservative elements, such as chloride, to the aquarium.

• Improves upon the industry-standard powdered calcium supplement over the past three decades.

• Formulated by a marine scientist.

Calcium, magnesium, and strontium are required for the formation of aragonite, the skeletal material of reef-building invertebrates such as corals, clams, tube worms, and their respective allies. Brightwell Aquatics Kalk+2 provides these elements and may also be used to help regulate pH in reef aquaria. Kalk+2 does not contain chloride salts, which is a strong point for some hobbyists. The use of kalkwasser-type products remains very popular with many seasoned hobbyists, regardless of innovations in calcium-delivery methods.

Instructions and Guidelines

Kalk+2 is intended for use by experienced hobbyists who are familiar with kalkwasser (calcium hydroxide-based) products. The calcium concentration (”[Ca2+]”) and pH in the aquarium should be determined by using an accurate test kit prior to supplementing. Do not add this product directly to an aquarium without diluting in water as directed, and do not overdose; it must be added in a controlled fashion with a dosing device. Create a stock solution by dissolving 6 grams (~1 tsp) of Kalk+2 in 1 US-gallon of fresh water (preferably purified) and allowing at least one hour for any settling to occur; each ml of the saturated sol’n will increase the [Ca2+] in 1 US-gallon (3.785 L) of water by 2.3 ppm, strontium concentration by 0.04 ppm, and magnesium concentration by 0.06 ppm. Decant only the clear solution into the aquarium.  Discard any sediment.  This decanted solution must then be dosed/dripped into the aquarium at such a rate that salinity does not fall below 1.021 g/cm3 and pH does not increase by more than 0.1 every hour, nor is it ever allowed to exceed a value of 8.5. Dosing at night when pH in a reef aquarium is naturally depressed is often performed to avoid exceeding the maximum allowable pH value. If the [Ca2+] in an aquarium is gradually dropping despite using this product as directed, the rate of evaporation may be insufficient or pH may be too high to dose sufficient calcium to compensate for the rate of removal by reef-building aquarium inhabitants and/or undesirable chemical reactions. In this case, a secondary calcium supplement may be needed to occasionally re-establish the natural seawater concentration of calcium in the aquarium.

Aquacadabra acts as credit broker/intermediary and not as a lender.

Klarna's credit products are provided by Klarna Bank AB, which is authorised and regulated by the Swedish Financial Services Authority, with limited supervision by the Financial Conduct Authority. More information can be found here.

Newpay finance options are provided through Deko’s platform by NewDay. P.D. Aquatics Ltd, t/a Aquacadabra is an Introducer Appointed Representative of Pay4Later Ltd, t/a Deko, which is authorised and regulated by the Financial Conduct Authority (ref no 728646) and is a credit broker, not a lender. NewDay Ltd is authorised and regulated by the Financial Conduct Authority (ref no 690292) and is authorised by the Financial Conduct Authority under the Payment Services Regulations 2017 for the provision of payment services (ref no 555318). More information can be found by clicking the newpay option above, or in the Newpay FAQs.

We really want you to be happy with the product that you've received. If however, when the goods arrive they're not what you want, then no problem - we have a 60 day no quibble return guarantee. Just let us know that you're going to return the item(s) by contacting us(stating your Order Number) and complete the returns packing slip that will have been included with your delivery. This will help us to quickly identify the item that you have returned (unopened and unused) - and we'll put a refund through for you.