I normally use b ionic two part to dose since it includes trace elements as well.
Just to clarify, ESV B-ionic is not useful to supplement trace elements, and that is not why they are there. If you want to supplement trace elements with a two part, you either need to use a different brand that adds them for that purpose, or use a separate supplement.
Heres a copy and paste from a different thread explaining this issue:
Don't be confused by the elements in ESV B-ionic. They ARE NOT a way to offset any consumption of those elements. Same applies to Balling Part C. Using each of these methods may actually lower an element if it is higher than NSW concentrations, and both act exactly like a tiny water change each day.
Here's how that works.
The main ingredients in ESV are sodium carbonate and calcium chloride.
After a coral uses the calcium and carbonate, sodium and chloride are left, raising salinity.
Since folks maintain salinity, there is a slight salinity correction needed.
Each time you make such a correction (whether you realize making the correction or not, but, say, skimming), the concentrations of ALL ions declines. For example, potassium declines from that salinity correction.
ESV (and TM in Balling Part C) add back exactly that amount of, say, potassium, lost by the salinity correction, and potassium is back to normal, In fact, everything is ideally back to normal.
Not all two parts act this way. Some claim to add extra trace elements, and that is fine, but ESV and Balling do not are thus are not ever intended to compensate for consumption of, say, potassium, by organisms.
Thus, ESV B-ionic does not contribute to overdosing any trace elements.
