Strange ICP test results

Joe Batt · Apr 17, 2018

Hi Randy and everyone else too

I have just restarted an aquarium with cycled dry rock ( cooked in a trash can for 2 months after being cleaned with acid and bleach ) I also used lanthanum to lower any remaining phosphates. I thoroughly rinsed the rocks prior to adding to the new tank.

I started the tank with 0 TDS RODi water and Tropic Marin salt which gave excellent initial readings of Kh - 7.7dkh Ca - 440 Mg -1290.

I sent Triton the initial starting point with the water straight from the tank the same day as it was filled. The results are attached below Basically, I have very high Iron Manganese and Zinc.

The recommendation is 6x 15% water changes, yet the water was 100% fresh to start with, so I'm not sure why the problem.

Now my questions.....Are these levels harmful? How can I reduce them to acceptable levels?

(6x15% is a reduction of 62.3% contaminants. I was thinking of 2x40% water changes using another salt (gives 64% reduction in contaminants)? The tank only has rock and fish in at the moment)

Tuffyyyyy · Apr 17, 2018

I don't know if I'd worry about it. Maybe do a water change or two but the ICP test could be incorrect.

Joe Batt · Apr 17, 2018

Realised I forgot to add the result. All the rest was green and fine.

Randy Holmes-Farley · Apr 17, 2018

Those metals are pretty high, but I wouldn't go to water changes as that might be the source.

Any metals in the tank? Hose clamps?

Do you have a float switch in the RO/DI (we've seen rusting wing nuts).

rkpetersen · Apr 17, 2018

Those really do suggest corroding metal. The high iron is pretty surprising, as it doesn't usually hang around long; even when I had some contamination that was traced to a prematurely rusting pump, the iron level stayed at or near zero.

Whether or not you identify the source, I'd probably put a polyfilter in a high flow area of the sump for a while. May have some effect on lowering those levels.

Joe Batt · Apr 17, 2018

Nope, no metal in the tank, no metal hose clips and no rusting screws in the RODI unit float switch, its 100% plastic ....
I'm really not sure what to do, any suggestions? If I add any corals at the moment I'm worried I will lose them with these levels.
I was expecting the ICP to show pretty much normal levels of everything, or at worst having to add something.

Leave it running a month or so with just the fish and retest?
Test the RoDi water direct?
Get a different companies ICP test?
Get a load of water from another source ie LFS to do a water change and re-test?

Flippers4pups · Apr 17, 2018

What's your TDS going into your DI?

DesertReefT4r · Apr 17, 2018

Do you have sand in the tank? New or old? I used some old sand and found it had a ton of iron in it. Dropped a Hydor magnet one day and it landed on the sand, picked it up and it had a bunch of black iron on it. Thought it was black and white sand mixed. Check your pumps, any metal impeller shafts can rust. It could be the salt mix as well but TM is pretty high quality and has good consistency and QC. Not unheard of though.

rkpetersen · Apr 17, 2018

Joe Batt said:
Test the RoDi water direct?
Get a different companies ICP test?

You could send a sample to ATI. Includes testing of your RODI.

Joe Batt · Apr 18, 2018

New dry rinsed sand. I have a large filter station for the water coming into the house and my input TDS is 5 to the RoDi with 0 as output.

All my pumps and impellers are in good condition. When I reset the tank I cleaned and disassembled everything.

Flippers4pups · Apr 18, 2018

Got to be incoming water or is it possible the rock are leaching out?

Randy Holmes-Farley · Apr 18, 2018

As to the question of harmful or not, I don't think we have a good handle on that, but they may not be.

Joe Batt · Apr 18, 2018

I have re-sent a fresh aquarium sample and also a sample from my RODI. Will be interesting to see the results.

With 0 TDS can the water still have zinc manganese or iron in it? I was under the impression that 0 was 0, nothing except pure H2O?

As for the rocks, that could be a possibility. I know they can leach phosphate, but they were acid bathed and bleached so I would have expected anything that was bound up in them to be in the surface layer that was removed with the acid process?

vegamedic · Apr 18, 2018

Joe Batt said:
With 0 TDS can the water still have zinc manganese or iron in it? I was under the impression that 0 was 0, nothing except pure H2O?

from "the other" forum:

"There are all sorts of non-ionizable organic contaminants that could be in water at substantial concentrations and still yield a reading of 0 TDS by conductivity. There are also many ionizable substances, including metals like copper, arsenic, zinc, etc... that could be in the water at too low of a concentration to register on a conductivity meter (which is what a "TDS meter" is, btw)."

Joe Batt · Apr 18, 2018

rkpetersen said:
Whether or not you identify the source, I'd probably put a polyfilter in a high flow area of the sump for a while. May have some effect on lowering those levels.

Does Polyfilter remove Iron, Manganese and Zinc? I think it does Iron so that's a start but Manganese and Zinc I couldn't find mentioned.

cmcoker · Apr 18, 2018

Joe Batt said:
Does Polyfilter remove Iron, Manganese and Zinc? I think it does Iron so that's a start but Manganese and Zinc I couldn't find mentioned.

Dont know for sure on the Boyd polyfil but Metasorb does list removal of all three