AWT Results - consistency questions

[lactose]

As seen from other posts I have been using the AWT service.

Without going into my reasons I really want this service to work. I have an email into them again on this as well and hopefully I will get an answer that allows me to move forward.

For all intents and purposes I am only interested/focused in on the following measurements:
Ammonia, Nitrite, Nitrate - "Health/Stress"
Phosphate, Silica - "Algae Control"
Alk, Calcium, Magnesium - "Reef/pH Support"

I have so far sent in 3 samples.

Sample #1: Display tank water taken Sunday evening 11/4
Sample #2: Fresh batch of newly mixed to 35 salinity of RC that sat for 36-48 hours taken 11/11
Sample #3: Display tank water taken Sunday evening 11/11
(between 11/4 and 11/11 no water changes or additives were made, the only "change" was that on 11/4 I replaced my phosphate media - which was rowaphos - to new batch of phosar HC)


AWT Results:
(first the display tank results)

Sample #1
Ammonia (NH3-4) 0.004 Good
Nitrite (NO2) 0.004 Good
Nitrate (NO3) 0.5 Good
Phosphate (PO4) 0.14 Good - this one was higher than what I had been seeing in Merck tests
Silica (SiO2-3) 3.8 High
Potassium (K) 373 Good
Calcium (Ca) 382 Good - this one was lower than what I had been seeing in API etc. tests
Boron (B) 2.1 Low
Molybdenum (Mo) 0.1 Good
Strontium (Sr) 7.8 Good
Magnesium (Mg) 1311 Good
Iodine (I¯) 0.02 Low
Copper (Cu++) 0.02 Good
Alkalinity (meq/L) 2.02 Low

Sample #3
Ammonia (NH3-4) 0.003 Good
Nitrite (NO2) 0.004 Good
Nitrate (NO3) 0.4 Good
Phosphate (PO4) 0.01 Good
Silica (SiO2-3) 0.7 High
Potassium (K) 368 Good
Calcium (Ca) 493 High
Boron (B) 4.5 Good
Molybdenum (Mo) 0.2 High
Strontium (Sr) 7.2 Good
Magnesium (Mg) 1181 Good
Iodine (I¯) 0.03 Good
Copper (Cu++) 0.02 Good
Alkalinity (meq/L) 2.01 Low

So as you can see the Ammonia/Nitrate/Nitrate tests were consistent with each other and what I had been testing so I am happy with that.

The Phosphate and Silica tests went *way* down in one week. So either there was a change in their testing (which they say they are working on but haven't given details) or Phosar HC really did a great job (and I did put a good amount in the reactor and heard locally very good things about it - so it is possible). Thoughts?

For Alk, Mag, and Ca.
Alk stayed consistent and where I had been measuring so that seems fine. (as a side note I am working on bringing this up as I am just now adding frags to the tank and need to bring this up a bit)
Mag went down from 1311 to 1181 (loss of 130 in a week) and I had been measuring ~1240-1280 in my tests prior to 11/4 so not too worried here.
Ca however went from 382 (which when I asked they stood behind) to 493 in a week with no additives/water changes. I have to believe they changed their test procedures on this one. 493 is closer to where I had been measuring with different test kits (API, Seachem, Salifert) in the 440-500 range so I am thinking they "fixed something" here. (see sample #2 for another eason I feel the second number is more correct) - thoughts?

Sample #2 (fresh made RC salt at 35 after sitting for a 36-48 hours - just as I would do before a water change) this was tested on the same day as Sample #3

results:
Ammonia (NH3-4) 0.002 Good
Nitrite (NO2) 0.005 Good
Nitrate (NO3) 0.4 Good
Phosphate (PO4) 0.01 Good
Silica (SiO2-3) 1.5 High
Potassium (K) 308 Low
Calcium (Ca) 410 Good
Boron (B) 4.0 Good
Molybdenum (Mo) 0.1 Good
Strontium (Sr) 8.5 Good
Magnesium (Mg) 1173 Good
Iodine (I¯) 0.03 Good
Copper (Cu++) 0.03 Good
Alkalinity (meq/L) 4.04 Good

From my past tests and research this "feels" about right where s=35 RC salt should come in which makes me feel good about the new measurements other than Mag seemed a little low (like in my display sample). The one interesting thing to note is the 1.5 for Silica which is higher than display tank. This could be an indication I am getting Silica out of my RODI or that there tests are still a little off here. (Note if you see the Am/Nitrite/Nitrate numbers and think they should be zero my two thoughts are that one they are pretty low and two the short version of how I do water changes is take a 20 G tank that was "inline" with my system, take it offline, empty, wipe clean - which I skipped that day, fill with premade RODI water, mix in salt, sit, etc. then put back in line and it could be that not wiping left crud on bottom/sides that contributed Am/trite/trate/phosphate/silica to this 'new' water.

So that is my AWT story, I wanted to include it for reference when looking at AWT and to gather anyone's thoughts. I think for now I will keep using them and keep measuring my Ca/Alk/Mag until I feel confident in their approach and not worry about Silica/Phos etc. until someone declares them way off or I see problems.

Thanks.

[cd77]

I think the problem quite clearly here is that you need to switch to using AB Reef Salt.