Magnetic food defroster

[Nordy]

Hey,
I was wondering if magnets pull iron out of the water column? This frozen food defroster I stick onto the glass has been pulling black specks onto its surface. I am nervous because the magnet might be exposed to my tank water through the seems of the casing. This is the second defroster for frozen food I’ve used in the last 7 months. The last feeder was the same, and collected a lot of black on the outside of the magnet. I just bought a new one out of fear it might be emitting toxins in my tank. I dose iron. My aquarium glass is 3/4” thick, so I bought a stronger magnet from Amazon to hold the feeder in place through my glass. Could this be causing an issue?

 

[KrisReef]

Maybe cause an iron deficiency in your tank & fishes?

I wonder if that is iron (contamination) from processing?

Interesting observation? Bump for wisdom.

 

[Shirak]

I would be more concerned as to why you have particulate iron circulating in the tank. Do you have black sand or rock? Iron dosing should be all liquid. Nothing to stick to a magnet.
Have you ever done and ICP to find out what your Fe levels are in the water? Thoughts Randy on dosing iron supplements and strong magnets? @Randy Holmes-Farley

 

[Nordy]

I sent away a new ICP Sample last Wednesday. I’ll post the results next week when I get them. No black sand in my tank. Here are some pics of the old feeder. Last picture is of my current feeder on the tank glass currently with the black stuff on it. Almost reminds me of the residue that comes off rubber suction cups used in tanks.

 

[Nordy]

My first ICP, I had very high iron, second ICP last December, my iron was zero. Thought maybe a piece of metal was in my tank somewhere causing the excessive iron initially. Now I have around 50 corals and my chaeto in the refugium has been growing a lot lately. It will be interesting for me to see the most recent ICP number on iron with the tank growth and the trace elements I dose every other day that contain iron.

 

[Shirak]

My first ICP, I had very high iron, second ICP last December, my iron was zero. Thought maybe a piece of metal was in my tank somewhere causing the excessive iron initially. Now I have around 50 corals and my chaeto in the refugium has been growing a lot lately. It will be interesting for me to see the most recent ICP number on iron with the tank growth and the trace elements I dose every other day that contain iron.

What iron supplement are you dosing? I dose iron too but have never seen particles attracted to my magnets. Do you see it on any other magnets like powerheads, pumps, impeller magnets etc??

 

[Nordy]

What iron supplement are you dosing? I dose iron too but have never seen particles attracted to my magnets. Do you see it on any other magnets like powerheads, pumps, impeller magnets etc??

I’m going to take off a gyre tomorrow and take a good look. I kinda just think it’s the feeder. I clean it every other day. Sometimes I will soak it in RODI water with vinegar. Maybe that’s the problem. I remember browsing a thread on the forum and someone mentioned there magnetic algae scraper was left inside the tank for a long stretch and had a magnet leach something toxic in there tank water. Then another thread I looked at was about pumps and not using vinegar for cleaning them for a greater lifespan if I’m recalling it correctly. My thinking is the magnet inside the casing is getting exposure to saltwater. Maybe my vinegar cleaning routine is exacerbating a weak enclosure against the saltwater.
These are my additions containing iron currently.

 

[Nordy]

Took apart an mp 40 today and cleaned it. Nothing around impeller or magnetic areas that resemble what is around the feeders magnet. Thinking I might trace a line of reef epoxy on the feeders magnet case seems. I’ll post my ICP results this coming week when I get them.

 

[slingfox]

Citric acid is the more gentle alternative to vinegar. You can purchase a large container for cheap at your local grocery store or Amazon.

 

[Randy Holmes-Farley Verified Community Expert]

Dissolved iron ions are not attracted to a magnet. It takes particles to respond to a magnet.

 

[Shirak]

Possibly related to soaking in vinegar to clean and causing issues with the magnet but usually this causes the magnet to rust and swell and crack the plastic. This sure looks like something in the water magnetically attracted to the feeder.

What’s the texture of the stuff accumulating on the feeder magnet? Is it gritty or fine and powdery?
Are all the supplements clear or are any cloudy?

 

[Sisterlimonpot]

I'd like to see some photos that are taken without blue light.

I can't make anything out with the provided photos.

 

[Nordy]

Here’s what I got. Still sticks onto the magnet only, doesn’t come off. https://www.triton-lab.de/en/showroom/icp-oes/221705

 

[Shirak]

Well that is weird for sure! At least it's not showing up in the water analysis that I can see so that's good. Still looks like something being attracted to the magnet pull and the only thing I can think of is one of the supplements you are dosing. Are they going into the tank near the feeder? Or maybe return from the sump near the feeder if you dosing into the sump?

 

[Nordy]

I do dose about a half a foot from the feeder because there is a gyre, and an mp 40 below. But honestly I dose sump near return pump, and sump before refugium. I have a lot of flow. One wavemaker in sump, 6 gyres, an mp 40, and two return outlets. If I’m multi dosing, it is in tank and in sump around return, or by wave maker before refugium.

 

[Nordy]

Think I might get one of those floating rings to hold a cube of frozen. U guys like that method for feeding frozen? If I’m home, I put frozen in a cup with garlic and vitamins, let it soak a half hour, then turn off my return so it doesn’t go to the over flow. But I have the magnetic feeders so my family can drop a cube of frozen when I’m away.

 

[Shirak]

When I would drop a frozen cube into my floating ring it would stay for a little bit but never until it was fully defrosted. Didn't do a super job for frozen cubes.

Why stop using the magnetic feeder? The plastic looks intact and your ICP looks fine.

 

[Nordy]

When I would drop a frozen cube into my floating ring it would stay for a little bit but never until it was fully defrosted. Didn't do a super job for frozen cubes.

Why stop using the magnetic feeder? The plastic looks intact and your ICP looks fine.

I don’t know the facts, but I remember reading about an exposed magnet causing a tank crash. I don’t know what a magnet would do under prolonged exposure to saltwater, I’m just uneducated and paranoid to my reef water fouling. But if you think all is well, I’ll continue using it.

 

[Nordy]

Still fighting with the Iron, seems to carry more weight against my efforts to have a somewhat acceptable value. Black specks are still on equipment that use magnets. Did my last ICP Dec. 23rd with Tropic Marin, got the results on the 7th of this month. There are a guild of trace elements I am working to have on target, a few low, a couple too many jacked up, but I’m curious how anybody would tackle my Iron Value? Was going to go ahead and try the Tropic Marin product to see if I can get a friendly reading on a future ICP. Anybody use there recommendations in the 3rd picture?

 

[Nordy]

A little Leary of the Phos-Feed they recommend. I do have an elevated LC reading currently, so I’ll check there ingredients on that or E-mail Tropic Marin.