Stainless filter screens

[Treebeard]

Relating to my question on clear pvc fittings and my efforts to build an inline filter for my phosban reactors, I stopped by the UFA at lunchtime and found inline filter housings with what I think are stainless steel screens. They are a dull silver color. Is stainless steel a no-no in a reef tank?

[NuraNori]

My dad's a machinist so I've heard a lot about different types of metal...

Stainless steel should indeed remain rust free...however it is fairly expensive. Have you ever bought a stainless steel knife and gotten a rust spot on it? I have. Turns out you can coat something in a stainless steel coating and still sell it as true stainless steel. So personally I wouldn't trust it...

If it's not too expensive you can always buy one stick it in a glass of saltwater for a month and see if it holds up...

I guess I've just become skeptical of "stainless steel" over the years...

[fkshiu]

There are many different kinds of stainless steel and only certain ones are non-reactive in saltwater. You should do more research first.

The other question is why is the reactor sponge gumming up in the first place. I have two running in series with GFO and carbon and have never had any clogging issues.

[RCFA]

You could try an inline y strainer. I use one after my pump on my hydropanic setup so the spray nozzles do not get clogged. It is made out of PVC and the strainer is all plastic with what I think is a nylon mesh. It works great. I have to clean it every couple of days but it really does a good job of mechanically cleaning sediment out of my system. I will try to get a picture of it you want but you should be able to get one at any hydroponic store.

[Treebeard]

Simple answer....I have a very successful hair algae farm and whenever I am "harvesting" some inevitable ends up in the sump and in the reactor filter.


The other question is why is the reactor sponge gumming up in the first place. I have two running in series with GFO and carbon and have never had any clogging issues.

[sphelps]

All stainless steel can corrode, it resists corrosion because of the chromium alloying agent which reacts with oxygen to form a film of chromium oxide which protects the internal steel. However oxygen is required, you'll notice many stainless steel parts will show signs of corrosion over time in areas of contact with other surfaces. For example your stainless steel coral shears corrode around the pin first and spread outward. Also your kitchen knifes corrode in the dishwasher if you put them on the rack (the rack stays in contact with the knife surface preventing oxygen to react with the chromium in those areas).

So in short no stainless steel should be used long term in aquariums, especially saltwater, any contact points on the metal will eventually corrode like any other steel.

[Treebeard]

The Y strainer sounds ideal, but the ones I saw online in the U.S. were expensive.

You could try an inline y strainer. I use one after my pump on my hydropanic setup so the spray nozzles do not get clogged. It is made out of PVC and the strainer is all plastic with what I think is a nylon mesh. It works great. I have to clean it every couple of days but it really does a good job of mechanically cleaning sediment out of my system. I will try to get a picture of it you want but you should be able to get one at any hydroponic store.

[Treebeard]

Thanks for the explanation. I will drop that idea.

All stainless steel can corrode, it resists corrosion because of the chromium alloying agent which reacts with oxygen to form a film of chromium oxide which protects the internal steel. However oxygen is required, you'll notice many stainless steel parts will show signs of corrosion over time in areas of contact with other surfaces. For example your stainless steel coral shears corrode around the pin first and spread outward. Also your kitchen knifes corrode in the dishwasher if you put them on the rack (the rack stays in contact with the knife surface preventing oxygen to react with the chromium in those areas).

So in short no stainless steel should be used long term in aquariums, especially saltwater, any contact points on the metal will eventually corrode like any other steel.

[Pescador]

You might also try inline filters for bilge pumps on boats, they are cheap and have clear plastic covers. you will still might have to swap out the stainless screen for plastic. Maybe CdnTire?

Here's one for an example
http://www.boaterbits.ca/review/product/list/id/290/category/90/

Maybe a filter bag on your overflow line in the sump would help as well.

[RCFA]

I got mine for about $15 bucks at quick grow on edmonton trail if you are in calgary. They have a couple sizes to fit your piping as well.