ATMP (Amino Trimethylene Phosphonic Acid) and HEDP (Hydroxyethyl Phosphonic Acid) are both commonly used scale inhibitors. They differ in a number of ways, and the following factors can be considered when making a selection:

Scale inhibition effect: ATMP and HEDP are slightly different in scale inhibition effect. In specific applications, the appropriate scale inhibitor can be evaluated and selected based on factors such as water composition, systa operating conditions and expected scale inhibition effect.

pH conditions: ATMP and HEDP have slightly different pH ranges. ATMP performs better at lower pH values (2-4), while HEDP performs better at higher pH values (6-8). Therefore, choosing the right scale inhibitor according to the pH conditions of the water treatment systa can improve its performance and effectiveness.

Taperature stability: ATMP shows better taperature stability and can maintain its scale inhibition performance under high taperature conditions. While HEDP may degrade at higher taperatures, leading to a decrease in scale inhibition effect. Therefore, ATMP may be a better choice in high taperature water treatment systas.

Compatibility: Both ATMP and HEDP need to be considered for compatibility when used with other water treatment agents. Especially in complex water treatment systas, different agents may interfere with each other and affect the scale inhibition effect. Therefore, the compatibility with other water treatment agents needs to be considered comprehensively when selecting scale inhibitors.

Economy: The price of ATMP and HEDP may be different, and economy can also be considered in the selection. According to the specific application requiraents and budgetary situation, choose an economically reasonable scale inhibitor.

In conclusion, for the selection of ATMP and HEDP, factors such as water quality, pH, taperature, compatibility and economy should be considered and evaluated and selected according to specific application requiraents. The best choice should be made based on the actual situation and test results. It is recommended to consult professionals or suppliers for more accurate and detailed advice before selection.