K&J Magnetics Blog about using magnets in aquariums

[tebstan]

Many of use magnets in our aquariums, some equipment comes with them and sometimes we make our own shelves and racks. Someone here gave me the idea of making a shelf out of rock to isolate some aggressive species on the back wall.






I get my magnets from K&J magnetics, and I get their monthly newsletter and coupon. This month, they did a blog on using magnets in aquariums. It has some pretty good info for people considering making their own magnetic projects.

http://www.kjmagnetics.com/blog.asp?p=aquarium

The blog includes a chart letting you know which magnet to pick based on glass thickness and how much weight you want it to hold.

"...a pair of small D84PC-BLK magnets on either side of a 1/8” thick glass wall should hold with a force of about 1.39 lb. This means it takes 1.39 lb to pull one magnet away from the wall. How much force will it take to slide the magnet down the wall? If we estimate half that value, that would be about 0.7 lb."

I didn't know how much the rock would weigh when I ordered the magnets, so I just stacked a bunch of them until it held.

[BBQHILLBILLY]

really kool. What are you using to stick the magnets?

[Zen Reef]

I've tried their plastic coated magnets their hold isn't good at all. Wish thy had them in a bigger size. I tried those on a probe holder what couldn't have weighed more then 2 oz and it was a sad gold on a 55 gallon. They have an epoxy coated n52 that has a 44lb pull force and that one has a strong hold on my 1/2 glass. Just my experience..

[tebstan]

The same glue I use for frags, the thick stuff from Bulk Reef Supply. The magnets are coated in plastic so there's no risk of erosion. We gouged a magnet shpaed hole into the rock with a dremmel tool, glued it in, and put a few magnets on the outside I glass.

Don't underestimate the weight requirement - remember not just the rock weight, but the coral you'll be putting on it! One of my rock shelves tips annoyingly to the side.

[txav8r]

Those magnets have a copper coating under a epoxy coating.
If they ever get scratched, ditch them.

[bugj51]

is there any worry of leaching of metals?

I take apart hard disk drives and there are really strong magnets inside them. I wonder if they would be ok to use......

[tebstan]

yes, metals can leach


No! Don't use just any magnet.


The magnets with a coating are like anything else in life - nothing is perfect or guaranteed. I've had a frag rack magnet rust. There were no scratches or chips on them - apparently they didn't have a perfect seal. I haven't had any of the K&J ones have a problem, but the one I scratched up while trying to get glue off now stays outside the tank.

[mkengr45]

I am using aqua mags.....rocks with magnets. Pretty cheap. Just google aqua mags...they have been around for a while

[mkengr45]

I ordered some plastic coated neodymium magnets to try and increase the strength of these things. The reason being that I don't know how well they will hold once encrusted with whatever SPS or LPS I put on them. Most softies should not have enough mass to make the rocks fall off, but more dense corals are a different story.