# Rusting riccia pads damageable?



## jack-rythm (24 Sep 2012)

Hi everyone....

I bought some of these a couple months ago...

http://www.ebay.co.uk/itm/Riccia-Java-m ... 44b&_uhb=1

and I have started to notice they are rusting on the ends of the metal points.. I have shrimp in there and other fish and plants and im worried about the levels being thrown... am I right in thinking this is a very dangerous thing to happen?? Should people really be selling this online and not warning about rust? I assumed the wouldn't due to the fact that they were riccia ads but I was wrong.. Lesson learnt..

What do people think? is it safe?


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## ceg4048 (24 Sep 2012)

Hello,
     Not sure what "levels" you are referring to. If you're referring to Fe levels then as long as you see the rust it is a precipitate and is not dissolved in the water column. This is Ferric Oxide  (Fe2O3) which is generally insoluble and is therefore not an issue for fauna. In a strongly acidic solution the Fe3+ will become more soluble and this is the technique used by plants to convert Ferric Iron to Ferrous Iron for uptake.

Iron is a difficult enough element to get and is highly prized by plants. I can't see any problems here. There are lots of other things to worry about, like cleaning your tank water to remove the real dangerous things like organic waste.

Cheers,


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## jack-rythm (24 Sep 2012)

that answer is amazing. straight to the point. thanks buddy  Im seeing no signs of loss or damage and my plants or shrimp do not seem phased.. but i will monitor closely. 

thanks


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## dw1305 (25 Sep 2012)

Hi all,
I agree with Clive, the rusting isn't a problem as such. If you dumped a truly huge bit of steel or iron wool (or similar object with a very large surface area) in the tank it may use enough oxygen to (as the iron oxidised to Fe2O3) to de-oxygenate the tank.

It be more worried about what the rust-proof coating for the steel mesh was. Because it is rusting on the ends I don't think it was stainless steel, I think it was anodized or galvanised. If it was galvanised and the tank was below pH7, you could end up with toxic levels of zinc (Zn) in solution. 

I'd contact the seller and try and get him to replace it with some stainless steel mesh.

cheers Darrel


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## LondonDragon (25 Sep 2012)

I have known rust to kill mosses attached to the pads, riccia grows so fast that it shouldn't be an issue.


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## ceg4048 (26 Sep 2012)

Hey Paulo, I know this might sound like I'm an attorney hired to defend rust, but can it be confirmed that the moss died from rust? Suppose the moss died from poor CO2 and just happened to be attached to something rusty? People kill moss all the time with rust nowhere in sight.

Cheers,


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## jack-rythm (26 Sep 2012)

I agree, I dont think the issue is whether the rust kills the mosses as I have had many mosses do fine in the same situation. as for riccia It grows so fast and I trim it that there is no issue here. Im more concerned about what  dw1305 has said..

'It be more worried about what the rust-proof coating for the steel mesh was. Because it is rusting on the ends I don't think it was stainless steel, I think it was anodized or galvanised. If it was galvanised and the tank was below pH7, you could end up with toxic levels of zinc (Zn) in solution. '

this is my worry as I have planned my next whole set up using a complete 30cm squared mesh pad to drop into the bottom of my nano to grow riccia... All fish and shrimp are fine so far and its been maybe 3 weeks but I am noticing orange circle stains on the glass. I think this is an interesting little discussion going on here and would like to hear more.

Here is a photo of my issue to help people analise.. REALLY SORRY ABOUT QUALITY 












Thanks guys


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## ceg4048 (28 Sep 2012)

Hi,
    Well it does look ugly, no doubt about that. I guess if you don't want to change it out to a plastic you'll just have to do more frequent and large volume water changes. This will also solve the issue of possible Zinc solutes assuming the metal is a galvanized material. It's difficult to say exactly what species of Zinc compounds will form or  what concentration will develop because we don't know the rate of decay. The Zinc will form different soluble compounds depending on pH, Alkalinity, hardness, temperature, Oxygen levels and so forth. Also, the toxicity of the various compounds depend greatly on these same parameters. Hard water and water with high alkalinity reduces the solubility and the toxicity. It's not clear if this is a CO2 injected tank, but the presence of CO2 induces formation of zinc carbonate which is mostly insoluble and therefore provides some level of protection.

Again, we don't really know what material we are dealing with. If the metal was anodized then this is not a big deal because that's done with acids to form an Iron Oxide coating which is not an issue. If it was painted over the oxide, and if the paint is dissolved that's something else entirely. Difficult to say without knowing. Sorry...

Cheers,


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## jack-rythm (28 Sep 2012)

well I think I will take it all into consideration, I have learnt alot from this post even if I have not found out exactly what it is I need to find out. Still opens my eyes to possibilities so thanks guys, ill monitor the situation doing water changes regularly..


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## ceg4048 (3 Oct 2012)

Hi,
    Here is what I find so incredible in this hobby. It's the reason we have so much difficulty, because we refuse to put the pieces of the puzzle together. Have you ever seen a substrate product like this?




Or how about Akadama discussed in JamesC's Akadama sticky in the substrate sub-forum?




In the Early days of planted tanks, everyone was hysterical about Laterite clay as a substrate. It was supposedly imbued with magical properties because of it's high iron content. Look at the color of these two products. It's exactly the same color as the rust shown in your first photo. Is this mere coincidence? The correct answer is No. The reason that the Laterite and Akadama have a rust color is because there is rust in their clay structure. The rust is the source of Iron in these clays. So somehow, it's OK if there is rust in the substrate, but if that same rust is on a nail or on a mesh, there is cause for concern, or it's accused of being a moss killer. Simply unbelievable....

Cheers,


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