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Zlements Range: Products

Please follow pHplus 2 Part dosing instructions:

Zlements Range: Products

Step 1

Determine the alkalinity consumption of the tank. This can be done by testing alkalinity, then stopping all dosing and testing alkalinity again exactly 24 hours later. The difference between the alkalinity levels will be the consumption in 24 hours. For example, if your first test reads 8.5 dKH, and your second test performed exactly 24 hours later reads 8.2 dKH, your daily consumption would be 0.3 dKH.


If you are already using a dosing system, please check our FAQ page for dosage calculation instructions then continue to step 3.


If you are already using Z-Complete, just simply replace Part 1 with P1 and Part 2 with P2. Your existing dosing volumes should remain unchanged (continue to step 3).

Step 3

Place the dosing lines over a very high flow/turbulent area or alternatively directly into the return pump (though don’t submerge the dosing lines). If you don’t have a high flow area in the sump this can be achieved with a small power head placed near the dosing lines. Please ensure that after dosing P1 it completely dissolves. Note: if P1 doesn’t completely dissolve it is likely to settle at the bottom of the sump as a white calcium carbonate mass, and will not work as intended. 

As good practice place the dosing containers is a stable and safe place to avoid any spills of pHplus, into the tank (e.g. avoid placing them directly on top of the sump or tank).

Step 5

Test alkalinity/pH daily and calcium every 3-4 days for the first 2-3 weeks.

During this time do not allow alkalinity or calcium to increase or decrease. If necessary to keep alkalinity and/or calcium stable, adjust P1 and/or P2 dosing volumes independently.


Test salinity weekly and ensure salinity is kept between 1.024-1.0264 SG or 31.9-35 ppt. Please note that high salinity will quickly lead to coral losses.

We recommend that you periodically check the water quality of your aquarium using our latest laboratory ICP OES DSOI analysis machine. Testing every 4 weeks whilst using our 2 part systems will give you the necessary insight and recommendations you need to keep your aquarium in top condition.

Step 2

With the alkalinity consumption determined, the daily P1 volume of Z-pHplus can then be calculated assuming that every 10ml of Z-pHplus will increase the alkalinity in 100 litres of water by 1dKH (you can use the calculator at the bottom of this page to calculate the dose).

Step 4

If you know your calcium daily consumption you can use Part 2/Universal daily dose calculator at the bottom of the page to calculate your daily dose.

Alternatively, if you don't know the calcium consumption and if your tank alkalinity is within 6.7-8 dKH and Calcium between 380-440 ppm, start dosing equal parts of P1 and P2 based on the P1 daily volume determined earlier. These doses should be divided into as many small doses as possible and dosed throughout the day (ideally at least one dose of each part per hour). Note: P1 and P2 should be dosed at least 15 minutes apart to avoid chemical interference.


  • If your tank alkalinity is above 8dKH, stop the dosing of any alkalinity solutions and allow your tank alkalinity to drop to a value between 6.7-8.0 dKH. Similarly, if your tank’s calcium is above 440 ppm stop all calcium addition until calcium drops to a value between 380-440 ppm.


  • If your calcium is above 440 ppm you should not begin dosing P2 until your calcium level is below the recommended value of 440ppm. However,  you can dose P1 as needed.


  • If your alkalinity is within the recommended range and your calcium or other elements are low, please use the individual elements we offer to adjust them. Do not attempt to use Z-pHplus to increase individual elements, e.g. Calcium, Magnesium, etc., as Z-pHplus was not formulated for this purpose, and doing so will likely result in the overdose of other elements.

Step 6

Enjoy your Reef Tank!

Safety Warning

DANGER - Causes severe skin burns and eye damage. Use protective gloves and eye protection. IF ON SKIN (or hair): Remove all contaminated clothing, rinse skin with water/shower immediately. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

IF INHALED: Remove the person to fresh air and keep at rest in a comfortable to breath position.

IF SWALLOWED: Rinse mouth. DO NOT induce vomiting.

Call emergency services immediately.
DISCLAIMER: Please ensure to only use chemical resistant dosing pumps and hoses/pipe like silicon tubing. 

Z-pHplus may damage bio-degradable 3D printed parts, some metals and non-chemical resistant plastics used in some aquarium equipment.

Reef Zlements cannot accept responsibility for the use of pHplus with non-chemical resistant equipment or damage cause by improper use.

In doubt please check with your equipment supplier before using.

Keep out of reach of children. Not for human consumption.

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