I have recently inherited a koi pond with a new house purchase. I have subsequently fallen head over heels for the hobby. My pond is approximatley 12.500 litres. In the centre of the pond is a decorative vase with water sprayer. The base which goes to the bottom of the pond is a metal and is also attached to two of the walls of the pond. The metal is covered by what looks like rust. I am sure that this is poisonous, but not sure what the consequences are. Photo below
So to summarise
1. What are the consequences of rust
2. Is there a chemcial solution for this or would I have to empty the pond and physically remove.

PS there were 6 fish when we bought of which 2 have died. One of the reaining has cloudy eye on one side (fan tail goldfish) and various bumps that look like pimples. The other large Comet looks like he is losing his colour (but I read that this is fairly natural for Goldfish.

Very new at this so any assistance would be greatly appreciated.[img]

Hi

Some info that might be useful

Metal
Symptoms: General illness symptoms, falshing, gasping, reddened gills, erratic swimming. Depending on the metal involved, confusion can set in without other symptoms being obvious.
Cause(s): There are many ways metal can enter the pond. Water from corroded pipes, improper decorations or equipment, nails, screws, coins, and even some medications which contain metallic compounds such as Copper Sulfate.
Generally, fish can handle only the smallest trace amounts of certain metals in the water. Metals bind to gills and other tissues, effectively stopping proper functioning. One or more organs can become affected at a time. Iron seems to affect the primarily the gills, lead the nervous system, and copper can affect the whole body, especially the liver.
To further guard against introducing metals into the tank, make sure that everything you use in and to do with the pond is metal free and in good condition. Plants and rocks from polluted sites may contain metal contaminants. Old equipment may degrade and release metals into the water. For example, cheap nets can develop rust which will be introduced into the water every time you use it
Metals can accumulate in the organs of aquatic life, causing a variety of physiological problems, ultimately leading to disease outbreaks and death. High levels of one or more of these heavy metals cause rapid death of fish and amphibians without obvious symptoms of disease or tissue damage.


Safe Metal Limits:

Copper 0.014mg/l More toxic in soft water
Zinc exacerbates toxicity
Combined both are dangerous
Zinc 0.01mg/l Synergistic with copper
0.15mg/l In hard Water
Cadmium 0.03mg/l
Chromium 0.10mg/l
Lead 0.01mg/l In soft Water
4.00mg/l In hard Water
Silver 0.03mg/l
copper continous: <.006mg/l
fish kill: >0.3.7mg/l in soft water, >.6-6.4mg/l in hard water
iron continous: <.1mg/l
fish kill: >0.5mg/l
magnesium continous: <0.01mg/l
fish kill: >75mg/l
lead continous: <0.02mg/l
fish kill: >1.0-31.5mg/l
Copper is the most poisonous of the bunch.
Although Copper is used in marine fish medicine quite frequently, in fresh water it's a different story. Copper accumulates in the fish's systems and is toxic at most any level in fresh water.
Even the lowest levels of Copper cause toxic changes in the fishes nervous system, gills, liver, kidneys, and the immune system. Fish exposed to copper over an extended period of time become dull, darkened and lethargic. At this initial stage of copper toxicity, gill lesions consist of the blunting of the gill lamella (significantly reducing the hemoglobin/O2 exchange). The gill filaments initially become severely hyperplasic (huge mucus buildups) and evolve to severe capillary congestion (telaglactisis) With continued exposure the fish become indifferent to any form of external stimuli -- the fish is basically suffocating to death.

I painted the inside of my small 3year old pond with ''waterblock''. This product will work to prevent the rust entering the water and the paint is non toxic to fish

Thanks for that input Marius.

I will also be worried about the different chemical reactions due to the iron in the pond when using medicine, for instance Potassium Permanganate.

Bottomline, no iron in a pond, rusted or not, unless you seal it properly with a very good waterproof sealant.

Just to add what Paul said.

I don’t say Potassium Permanganate is bad for treating fish but beginners like me should be warned about a few facts…..

Potassium permanganate, obtainable at pool supply stores, is used in rural areas to remove iron and hydrogen sulfide (rotten egg smell) from well and waste water. (What will the reaction be in a pond containing rusted metal???)

So why isn't potassium permanganate a godsend? Because using it is a little like using chlorine! Like chlorine, potassium permanganate is utterly unselective in its action. Oxidizers react with any organic: bacteria, protists, algae, DOC and particulate detritus-- but also the delicate epidermis covering fish gills. And the toxic level of KMnO4 is only slightly higher than its therapeutic level of 2ppm. For one thing, it will decimate the desirable nitrifying bacteria in your filter as fast as it acts on unwanted bacteria elsewhere. And some plants are extra sensitive to KMnO4: after a dose of potassium permanganate, Vallisneria can melt away as if it were Cryptocoryne

If you want to quickly deactivate KMnO4, you can do it with hydrogen peroxide, which is another caustic oxidizer with antibacterial properties. The H2O2 should be at a concentration of 1ml/15 liters: it will work in a few minutes. You should be aware that KMnO4 inactivates formalin and malachite green; the potassium permanganate will act as an antidote if they are all used together.

If you've unsuccessfully used salt in a fish pond to remove parasites and you then go and add potassium permanganate to the pond then it is quite possible that chlorine will be liberated in your pond. Salt and potassium permanganate can then react together under certain circumstances to produce chlorine. Why take the risk?

Salt when used in conjunction with zeolite can also release ammonia back into the pond water.

The importance is to alert you to dangers of adding anything to pond water. Sure at times it is necessary and important but any pond addition must be done with greatest circumspection, and a full knowledge of benefits and potential dangers. It goes without saying that the pond volume must be known with accuracy in order to get dosage rates worked out well.

The following is a well accepted fact ... A biofilter properly sized, installed and maintained prevents more than 90% of all pond problems

THanks for the repsonses. I will work on getting it removed. Just one more ?. Do I need to do a 100% water change once removed. My plan was to remove enough water to get into the pond (around 5000l) and basically cut out the base and seal whats left.

If you do a 100 % water change, you will loose the maturity of your pond and you put your fish under a lot of stress. I would do a 50% change, remove the iron, and another 30% in a weeks time.

Maybe Paul can comment on adding salt (about 37kg or 3%) to your pond after maintenance. This will help to prevent an outbreak of disease since you have disturbed the fish and environment and immunity will be low. You can lower the amount of salt every week with your partial water change by not adding salt to the new water

I agree, under normal circumstances I do not use salt. However, every time when there fish undergo stress, I add 3 kg/1000 liters. It creates a mucus layer to protect them from parasites and bad bacteria and limit the negative affect of high Nitrites that can be expected due to a loss of good bacteria after a large water change, apart from various other advantages mentioned under the discussions of salt on this forum.

It is also very important to test your water for a while for Ammonia and Nitrites after a large water change.

Hi,

You can use salt and potassium permanganate together!
Never treat muddy water with “pp” as this can promote the toxic Manganese dioxide on the gill filaments.
It can be used in an emergency to release available oxygen to Koi if there is a shortage of oxygen.
Potassium permanganate is very toxic to fry!
A complete water change should be effected after using in the pond. Particular attention must be given to cleaning the bottom of the pond.

Never use salt together with formalin or zeolite, or never use a galvanized bath/ bucket to “mix” potassium permanganate. A chemical reaction will release zinc into the water.

Hi julle, ek het 'n pobleem waarmee ek nou al lankal sukkel. Ek gebruik hierdie sainless steel filter "copy van 'n eazy" as my meganiese filter. Die probleem wat ek het is dat die ding roes. Ek is ook nie enigste persoon in die kaap omgewing wiesin roes...Die ander wat ook gekoop het is baie gelukkig met hulle sin.

Ek het my eerste "eazy" ingesit in Feb 2008. In December 2008 moes ek hom vervang want hy was gaar geroes. Hier is photos van merkies op die nuwe eazy wat ek gekry het as replacement in desember 2008.





Dis nou 5 maande later en die "nuwe eazy" is besig om uit mekaar teroes. Hier is photos.





Die vervaardige van die "eazy" claim dat ek elektrisiteit in my water het. En dat dit die stainless steel laat "pit" soos hy se. Op die onderste photo kan jy klein merkies sien, dit lyk soos vullis maar is eintlik baie klein gaatjies reg deur die metaal.



Is daar 'n manier om tesien \ check of daar krag in my water is? Ek swem gereeld in my koi dam en het nog nooit iets gevoel nie. Die visse doen almal reedelik goed, so ek weet nie.

Ek het selfs gewonder of medikasie verandwoorlik kan wees hiervoor? Die enigste medikasie wat ek gebruik het gedurende die jaar was Potassium en M & F.

Help asseblief.

See http://www.ssina.com/faq/index.html

"Stainless does not "rust" as you think of regular steel rusting with a red oxide on the surface that flakes off. If you see red rust it is probably due to some iron particles that have contaminated the surface of the stainless steel and it is these iron particles that are rusting. Look at the source of the rusting and see if you can remove it from the surface. If the iron is embedded in the surface, you can try a solution of 10% nitric and 2% hydrofluoric acid at room temperature or slightly heated. Wash area well with lots and lots of water after use. Commercially available "pickling paste" can also be used."

Hi Paul, so you are saying that there is a source of Iron in my pond water and that this iron is attached somehow to the stainless steel and its rusting.

That sounds like it can be possible.

But how does that explain the holes in the eazy? My previouse eazy really fell apart and if you look at image 5 you can actually see that the brackets are rusted off.

Wayne

I think that the product is not entirely stainless steel, because in your case the rust is severe. Technically, as far as I know, stainless Steel can not rust. I have been using stainless steel on my boats for years which is exposed to sea water on a regular basis, eg bolts to attach my engines, and it is still "stainless" You bought your eazy fairly recently.

I don't think electricity can cause that and you would have known about another source of iron, except if there is a lot of iron in your water(for instance borehole water)

Do you have a skimmer box? Most skimmer's use stainless steel screws to attach the rim to the skimmer. If so, see if they are affected.

Sorry paul, fibreglass skimmer on this side. and no bore-hole water either.

The eazy did come with a lid, which i did not use...its made of thicker stainless steel than the rest of the unit, i left it outside in the wind and rain but it does not have a scrath on it.

Im starting to think that i dont feed my bacteria enough.

Hi Wayne

I am in the telecom industry and on many occasions seen stainless steel corrode. You cannot for instance use stainless steel bolts on a galvanized sheet. Within months it will corrode away. I agree with Paul that in your case it might not be pure stainless steel

Some interesting facts:

For a wide variety of applications, stainless steel competes with carbon steels supplied with protective coatings, as well as other metals such as aluminum, brass and bronze. The success of stainless steel is based on the fact that it has one unique advantage. The chromium in the stainless steel has a great affinity for oxygen, and will form on the surface of the steel at a molecular level a film of chromium oxide. The film itself is about 130 Angstroms in thickness, one Angstrom being one millionth of one centimeter. This is like a tall building being protected from the rain with a roof the thickness of one sheet of ordinary copy paper.

There are over 150 grades of stainless steel, of which fifteen are most common.

Stainless steels are corrosion RESISTANT, not corrosion proof. Chlorides and fluorides and other substances can, and do, attack stainless steels.

Type 304 stainless steel is corrosion resistant but metals are not corrosion-proof. Type 304 stainless steel contains nickel and chromium and some other elements, but the principal ingredient is still iron, and what you are seeing is probably rust

Thank you marius for that detailed explaination. Lets say that the easy is made of a sub standard stainless steel why is only mine rusting...remember i have already had 2 from the same supplier...thats why the supplier is saying its my water or rather electricity in my water because nobody else is having this problem. For example Bobby on this forum has had his in his pond since October 2007 and has had no problems.

Can I be honest? I am lost and can not give you an answer.
If you look at the pattern of “rust’’ it seems that some other substance was in contact with the drum. Viewing the inside of the drum, it looks like the ring was made from iron and not stainless steel and welded to the drum. I will try my best to get more info about what is going on.
What I do know is that the potassium permanganate can’t attack steel

Hi Marius, the marks on the easy was definatly not caused by something being in contact with the drum. The drum sits in a vortex, so the water is spinning around it the whole time.

You can see it in the thread about my pond setup.
https://koionline.forumotion.com/posts-on-pond-building-f17/pond-progress-wayne-barker-32-000l-cape-town-t289.htm

Found the following bits and pieces for you. It does not give a clear indication of the problem since I am sure your water will be of good quality, but worth reading:

Chloride content of the water is the most important factor causing corrosion in stainless steel. Low pH will have an effect as well

MICRO ORGANISMS.

If the protective oxide layer is removed from stainless steel because of rubbing or damage, the "bugs" can penetrate through the damaged area and attack the carbon in the metal. Once in, the attack can continue on in a manner similar to that which happens when rust starts to spread under the paint on an automobile.

PITTING (need to read the web links below to fully understand )

This is an accelerated form of chemical attack in which the rate of corrosion is greater in some areas than others. It occurs when the corrosive environment penetrates the passivated film in only a few areas as opposed to the overall surface. As stated earlier, halogens will penetrate passivated stainless steel. Referring to the galvanic chart you'll note that passivated 316 stainless steel is located nine lines from the bottom and active 316 stainless steel is located thirteen lines from the top. Pit type corrosion is therefore simple galvanic corrosion, occuring as the small active area is being attacked by the large passivated area. This difference in relative areas accelerates the corrosion, causing the pits to penetrate deeper. The electrolyte fills the pits and prevents the oxygen from passivating the active metal so the problem gets even worse. This type of corrosion is often called "Concentrated cell corrosion".

http://www.gilsan.co.kr/eng/stainless/stainless4.htm

http://www.mcnallyinstitute.com/04-html/4-1.html

http://www.weldreality.com/stainlesswelddata.htm

http://www.recreonics.com/fyi/stainless_steel_maintenance.htm

http://www.healthywater.com.au/water_facts/waterfacts02.cfm?cat=commercial

Now im lost, this is so compicated....i feel like a noob.

Whats the solution for pitting? What must i do to prevent it?

These sites will explain the process of pitting (Concentrated cell corrosion)

NASA might not know much about ponds but I am sure they had a few metal related problems on the space crafts, lol.

http://corrosion.ksc.nasa.gov/conccor.htm

http://www.tpub.com/content/UFGScriteria/UFC3-570-06/UFC3-570-060020.htm

http://www.corrosionist.com/Corrosion_Type_Concentration_Cell_Corrosion.htm

http://corrosion-doctors.org/Principles/Cell.htm

Article on how to correct the corrosion:

http://www.gordonengland.co.uk/corrosion.htm

I think the ‘electricity in the water’ the guy referred to was more a matter of two or more areas of the same metal surface in contact with different concentrations of liquid that are causing an electrical potential between the large area of the cathode (passive film) and the small area of the anode (active metal). Rapid pitting of the active metal will result.
It is like sticking an electrode into a lemon and you get a small voltage or battery.

The question still remains what in your pond is causing this reaction since you are the only one having this problem. Hopefully someone can come up with an answer for you

Regards
Marius

Hi All, i think i have found something.

I tested my pond water today and found 0.2 ACV in my pond water but its only in my filters....my pond itself does not register at all. I am not sure how or why and so im checking my earth lines. I have a earthleackage of 0.6 from my house. With all the power off i still get a earth leakage of 0.1?...

The pictures below shows my municipal DB Box. If i look at the wire setup it looks wrong to me but i am no electrician. There seems to be a loop of some sort between the neutral and the earth wires. There are 2 incoming earth wires, a green and yellow and plain copper wire.

Are there anyone with a bit more knowledge than me in this subject?





The sticker mentions that the box is earthed on neutral. I have spoken to several people so far and no one has ever heard about doing it that way but non of them are electricians either so i guess it does not count either.

Since the neutral point of an electrical supply system is often connected to earth ground, ground and neutral are closely related. Under certain conditions, a conductor used to connect to a system neutral is also used for grounding (earthing) of equipment and structures. Current carried on a grounding conductor can result in objectionable or dangerous voltages appearing on equipment enclosures, so the installation of grounding conductors and neutral conductors is carefully defined in electrical regulations. Where a neutral conductor is used also to connect equipment enclosures to earth, care must be taken that the neutral conductor never rises to a high voltage with respect to local ground

Voltages created in grounding (earthing) conductors by currents flowing in the supply utility neutral conductors can be troublesome. For example, special measures may be required in barns used for milking dairy cattle. Very small differential voltages, not usually perceptible to humans, may cause low milk yield, or even mastitis (inflammation of the udder). So-called "tingle voltage filters" may be required in the electrical distribution system for a milking parlour.

Connecting the neutral to the equipment case provides some protection against faults/shorts, but may produce a dangerous voltage on the case if the neutral connection is broken.

Combined neutral and ground conductors are commonly used in electricity supply companies' wiring and occasionally for fixed wiring in buildings and for some specialist applications where there is little choice like railways and trams. Since normal circuit currents in the neutral conductor can lead to objectionable or dangerous differences between local earth potential and the neutral and to protect against neutral breakages, special precautions such as frequent rodding down to earth, use of cables where the combined neutral and earth completely surrounds the phase conductor(s), and thicker than normal equipotential bonding must be considered to ensure the system is safe
Where a ground connection has a significant resistance, the approximation of zero potential is no longer valid. Stray voltages or earth potential rise effects will occur, which may create noise in signals or if large enough will produce an electric shock hazard.

Stray voltage occurs when electricity “leaks” from the black wire directly to the red or ground wires before passing through the device to be powered. These leaks produce only small amounts of electricity

I think you have a bad contact somewhere. This can cause a voltage difference even within the same wire. To many joining points on the same wire can cause loop currents.

Best way to explain this is when you use thin wires to ‘jump start’ another car. You struggle to get the other car going and you ask yourself: ‘‘what is wrong, I have connected the flat battery to a good battery but still no luck’’
Well, do yourself a favor next time this happens. Measure the voltage on the good battery and then on bad battery while you turn the key. You might find let say 13.6V on good battery but only 9.5V on the bad side. This missing 4 volts is a result of a voltage drop within the wire itself due to resistance.

Just for a matter of interest. When you did your measurements, did to stick the one probe of the multi meter to the earth wire on the motor and the other end to the easy drum inside the filter??

Ok, found something else. the 0.2 ACV in my vortex filter seems to be coming from my speck porpoise 0.45kw pump that is sucking from the vortex which contains the eazy filter.. If switch it off the 2V disapear the same if i close the ball valve on it. I have 2 pumps and only the one seems to "leak" electricity as i also configured the other one to suck from the vortex and then there is no electricity in the water. So it seems to be a faulty pump.