Backyard Aquaponics
A place to discuss aquaponics

Has anyone used stainless steel scrubbers as a media for the bacteria to grow on? I found 1 page where someone suggested using it and listed it's incredibly high surface area relative to other media. It was compared to media such as pvc strands and for the cost, it seems to be much cheaper. I came across this one site that sold 72 (case) for about $26.50 not including shipping.

http://www.wernersponds.com/biofiltermedia.htm

http://www.reliablepaper.com/Large_Stai ... rubber.htm



I picked up some and I'm going to experiment. I just need to figure out a way to best implement it into my AP. I have some ideas but none that I am really happy about.

I purchased:
http://www.instawares.com/3675200-carlisle-flo-pac-stainless-steeel-scrubber.crl-3675200.0.7.htm

Simply b/c the product details told me the grade/series of the stainless steel (400) which allowed me to do a little more research so that I would feel safer about using it. I was worried about leaching of chemicals into the water. From what I was able to find out, stainless steel doesn't really break down until it is under conditions that would make my pond look like the apocalypse. eg. temps in the hundreds of degrees and PH that would melt my skin.

I did find that stainless steel is used in applications where bacteria is used in large columns to get rid of the sulfur smell of polluted water.

Hi Mike... That sounds like a great idea. I'm surprised, that they are cheaper then the pvc shavings. Plus, they have more surface area. Thanks for the info.

Most of us here are used to using gravel beds as our bio-filter/solids filter/plant growing space so we only rarely get into some of the alternative bio-filter media options.

However, I've read about using scrubbies and such in ornamental pond bio-filters and water fall filters and such. Heck, people even pack shade cloth into bins to use as filters. Scrubbies are a pretty good choice as they pack in fairly nicely from what I've heard.

Just set up a bin where the water enters at the bottom and flows up through the scrubbies, have something to keep the media from floating up and out and have the water outlet near the top.

Depending on size, you many need to clean it if solids start building up too much. I'm not sure how to size such bio-filters for Aquaponics since I know the gravel bed numbers better. When you find some sizing info, be sure to try and sort out if those numbers are with solids removal before the bio-filter or not. You may also want to design some way to add air into the bottom of the filter since a constantly flooded filter only has the oxygen that is in the water and it can be quickly used up.

Good Luck with it!

Wow, pvc is got to be making the plastics companies a fortune. I find it hard to believe stainless steel can be manufactured cheaper than PVC. It goes to show what creatures of habit we are as consumers. Good catch... the stainless may leach less than the Poly Vinyl Chloride... which acts like a synthetic estrogen on the cellular level. A little tidbit I got from the discovery channel on a show called attack on the male which predicts mankind to end based on decreasing sperm counts due to chemicals that act like synthetic estrogen and what we're feeding dairy cows to keep them producing, accumulation of estrogen in our water from birth control etc...
Sorry I'm drifting... good find!

I have a biofilter with green scrubbies. It works great but it is VERY under sized for my system. Its getting clogged pretty quick. Its a 16 gallon filter for a 300 gallon pond. I also have 100 gallons of gravel but very very underfiltered. I'd imagine I'd need to clean it after a while. I'm in the process of adding 100 more gallons of gravel.

I saw a site where a guy made his own pvc shavings. He had a lathe and took regular old pvc pipe and made shavings. It was super cheap and easy, I wish I have a lathe or access to one. You'd be surprised how much ribbon comes from a 6 foot piece of 1" pipe.

I know two people with wood lathes... I asked/hinted to one of them what he thought about making pvc ribbon and he said he thinks a metal lathe would be the proper tool for the job... not sure why as I didn't want to press him on the subject since he bought it as a hobbyist. I guess it might have something to do with how hard pvc is but I finally decided that I really didn't want to ask the other person to lathe pvc shavings for me since they use their lathes for making furniture professionally even though the prices that I've found seem pretty steep. $80 for a cubic foot or something like that. I really hope that 400 grade stainless steel scrubbies for food services won't cause me to grow a 3rd nipple or something. Haha Just kidding. I think I'm more worried about the fish but I'm not eating the goldfish. They spawn every year and I haven't seen any chimera baby fish or ones with 3+ eyes. I get worried enough about the estrogen like compounds found to be leaking out of Bisphenol A (BPA) type products and I don't even have any of those in the home. Then again maybe I should be more worried about the trace amounts of pharmaceuticals now found in drinking water all over the United States.

I don't use sites like these as a bible but more as a quick reference for further research for actual studies that are published in peer reviewed journals but here it is anyways.
http://www.care2.com/greenliving/which-plastics-are-safe.html#

I've read that these products that leach compounds become a problem when exposed to high temperature liquids (beyond what my AP system would experience) such as heated baby formula, microwaved liquids, water left out exposed to UV sunlight etc... and even then it's not like the plants are taking up the compounds and I don't plan on drinking my AP water. Every now and then the sparrows fly down and drink from the pond so perhaps I will use them as a mining bird like gauge.



TL;DR = I think stainless steel is safe

The stainless steel scrubbers that I use is either non magnetic or barely magnetic to the point where I can't feel the attraction to a magnet so I am going to assume that it might have nickel in it since nickel is one of the ways a stainless steel becomes non magnetic and in the:
400 series they all use Carbon, Manganese, Phosphorous, Sulfur, Nitrogen, Silicon, Chromium, Molybdenum
only 410 uses nickel but at .2 to .55 % by weight.

http://www.spiusa.com/Ref001/400prop1.html

This eased my mind a bit about using stainless steel:

http://www.odu.edu/~jrule/Biol695/pdf/1.pdf

Nutrient Element Biochemical Functions

1st Group: C, H, O, N, S
Major constituents of OM Involved in enzymatic processes

2nd Group: P, B, Si
Esterfication reactions

3rd Group: K, Na, Ca, Mg, Mn,Cl
Non-specific functions - osmotic potentials Anion balance; membrane permeability

4th Group: Fe, Cu, Zn, Mo
Catalytic enzyme rx’ns e- transport PLANT

Maybe in the worst case scenario I'll actually get lucky and metals do leach off of the scrubbies and provide micro nutrients such as molybdenum to my plants! So yea I haven't yet stumbled upon any studies that demonize stainless steel so I'll cross my fingers.

This website started my journey with using media other than rocks/clay for biofiltration. I thought about using those green scrubbing pads rather than stainless steel but I sometimes start overthinking "things" and I didn't know quite how to approach the thought of not knowing what the green pads are made of. I've used them in home made pots to keep the dirt from falling out of the drainage holes and I've noticed a dust like powder comes off of them. I read somewhere that their is a type of glue used to bond abrasive material to the pads and not knowing what the abrasive material, glue, and/or green fiber is made of irked me.
http://www.ericnewman.com/biofiltr.htm

p.s. I find the midi music annoying and the player is on the bottom right of the page.

Many of us bury rusty nails and tin cans in the grow beds to help provide iron which the plant needs to be able to take up the nutrients others dose with chleated iron. (easier) I thinke the stainless scrubbies is a great idea and may clean easier should you have to do that.

I use the plastic scrubbies in my bio filter. They work great.

Here is a link to a home made bucket filter. This isn't exactly like mine, but it's similar.

http://www.aquariumlife.net/print/article.asp?id=111

Mikeym, here's my filter design if you're interested. Works pretty good but like I said it needs to be bigger.

In my case I think I'd prefer the green scrubbies over the steel wool. To me (no information to base this, just from my observations) the green scrubbies look like they might catch solids better than the steel wool. I dunno just seems like you can create a better barrier than the steel wool. Both probably have the same bioconversion capacity.

oh sweet!

Thanks for the diagram, you just made me realize that I really should add a venturi (thing) to my inlet so that my DWC buckets/filter don't siphon back into my pond!



Inlet is on the left, outlet on the right, I positioned the joint on the bottom so that it makes sort of a swirling effect as the bucket fills up. I don't have enough stainless steel scrubbies to fill all 6 of my buckets up so I was thinking of just sticking the scrubby a little into the pvc and then holding it with a rubber band.

Yah the venturi works great to aerate the filter. it does however slow the flow of water.

Found the link to the DIY PVC ribbon page.

http://www.ericnewman.com/biofiltr.htm

Pretty cool. $32 for a cubic yard vs $600 bought.

I get green ScotchBrite pads at Sam's Club (they come in a box of like 16 or something) and have used them here and there for screening or to filter solids. They are the ones that are just the green rough stuff, no sponge attached and no soap built into the pad.

yep dave, got mine at costco. Pretty damn cheap! can't remember the price.