Attn. Analytical/Chemist types...

[RlxdN10sity]

I use TMG for micro dosing. I use an Aquamedic peristaltic pump to dose 7 ml a day in my 55 gallon. Today, just now actually, I was checking the output of the pump head by cycling and discharging into a 20ml flask.

The quantity was precise but the color of the TMG was unexpected. It was nearly clear. I drew some fresh TMG from my 1 gallon jug and put it into the same flask after rinsing it so as to compare. The fresh TMG looked nice, a dark brownish red.

I then dosed the pump again and this time the sample was a very dark green. I think the first sample could possibly have been dilluted from tank water that is constantly bypassing the T where the TMG would normally discharge into the water column. The second sample being so dark and greenish, is a mystery to me.

I dosed a 3rd sample and got the same result as the 2nd. A dark, sooty green color. Any ideas on what is happening here? I use Tygon tubing for 90% of the dosing circuit. The pick up in the dosing reservoir is a short piece of copper. The reservoir itself is clear schedule 40 PVC. Is the TMG breaking down? A significant portion of the Tygon circuit is exposed to light. Could this have something to do with it? Any ideas would be appreciated. Thanks.

 

[tedr108]

I cannot answer your question, but I've always put my TMG back in its box when not in use, just to be on the safe side ... even though it is an inconvenience. I'm hoping someone will post and say that light does not hurt it, so I can stop this.

 

[RlxdN10sity]

Lol. I think you can stop putting it back in the box.
I ordered a 1 gallon size container of TMG when I bought it. It comes in a semi-clear jug. I suspect if light was an issue they would bottle it in something completely opaque.

The TMG still in the jug looks as new as it ever did just judging by the color. I have went ahead and removed my reservoir to inspect TMG that is still in it. The entire reservoir is of this dark, sooty green color now. As I said earlier, I use a short piece of copper internal to the reservoir as a pick up to draw TMG from the reservoir.

The copper pick up is submerged in the TMG and is constantly full internally with the prime of the pump remaining static at all times so long as there is not a leak in the circuit.

Logic leads me to conclude that it is this contact with the copper pick up in the reservoir that has caused this reaction as the reservoir itself is in a location that is completely without light.

My question now is, what is this reaction and what is the net effect on the TMG in its ability to provide micros to my plants. The plants do appear to be suffering some deficiency.

 

[Mooner]

I cannot answer your question, but I've always put my TMG back in its box when not in use, just to be on the safe side ... even though it is an inconvenience. I'm hoping someone will post and say that light does not hurt it, so I can stop this.

Ted,

You are correct about putting it away as I do. I'm looking at the directions and I quote

"Do not expose the container to sunlight"

Now about room light? Probably not the best either.......

 

[Tom Barr]

It's just the oxidation of the DTPH is all, some HCL will help, but I'd not worry, just do not leave it out in the sun is all.

Regards,
Tom barr

 

[RlxdN10sity]

When you say DTPH oxidizing, are you referring to what happens in sunlight or to the reason why my TMG is turning dark green while in the reservoir with a piece of copper submerged in it? What is DTPH, a chealator? What is HCL? Thanks.

 

[VaughnH]

DTPH is a chelator for the iron and some of the other metalic elements in the trace mix. HCL is hydrochloric acid also known as muriatic acid - swimming pool acid. I think the color change you see is what Tom is referring to. And, you don't need to keep the trace mix in the dark, just not in sunlight.

 

[RlxdN10sity]

Thanks, Vaughn, and Tom.

So the bottom line here is that the TMG being exposed to the copper pick up line and oxidizing the chelator is not a detriment to the effectiveness of the TMG?

 

[Tom Barr]

Should be fine, you can email Tropica, they should say the same type of thing.
I recall years ago(10?), some folks had a similar question.


Regards,
Tom Barr