formaldehyde and paraformaldehyde information

[greg]

Duncan,

Yes thanks from me too. While i've not commented as such i have been checking the thread everytime there is a new post to see the updates.

Regards,
Greg.

[tomy2ponds]

HI Duncan thanks for all your hard work on this I will await your final results it looks like formalin and salt is ok after all

[Duncan]

Salt NaCl and Formaldehyde CH2O

Duncan Griffiths

In koi health, the one taboo has continually run through out the hobby and one that most hobbyists conform to religiously without questioning it and that’s the one that says “do not uses Salt NaCl with formaldehyde or formalin” with no real hard evidence to either shoot or salute this theory.

It’s a strange theory to be sure because no one knows where this theory originated from in the first place and there are certain contradictions that also seem to be as entrenched as this theory.

1. You can use formaldehyde with salt as long as the salt concentration is below 0.15% ( ¼ oz per imp gallon) no real evidence as to where this originated from but presumably the salt would be so insignificant it would be in effect like having no salt at all as typical water supplies can have 0.05% in which is a third of the former .
2. You can use formaldehyde and salt as long as the fish does not have any open wounds
3. Marine keepers use formaldehyde with salt they have no choice and their salt concentration is a round 3.5%, so you would think if there were to be an adverse effect it would occur here

The list of for’s and against are endless but the truth is nobody really understands where the taboos came from but folks do adhere to them.

With this in mind I decided to experiment to see if the truths were in fact exactly that

Back ground formaldehyde information

Formaldehyde is a gas in solution; with a maximum saturation of around 40% it has many industrial uses as well as a fixative and preserver

In the pond it behaves in a similar manner to Potassium permanganate in so much as it expends itself on organic loading in the water column the higher the carbon content the just like KMnO4 the faster its spends itself to the point where it becomes nonexistent

In a normal pond environment it’s usually gone within 8-12 hours should be stored out of sunlight and in warm conditions. Highly toxic with carcinogenic vapour

Formula CH2O
Freezing point -92 c
Melting point: N/A
Boiling point: 96 C
Specific gravity: 1.083
Vapour pressure: 55 mm Hg at 37 C
Vapour density: 1 (air = 1)
Flash point: 56 C
Explosion limits: 7% - 73%
Auto-ignition temperature: 300c
Water solubility: substantial

Methanol is mixed into the solution to create stability and increase its shelf life this then becomes formalin. If stored in cold conditions the solution becomes paraformaldehyde highly toxic and must not be used (paraformaldehyde is a clear to milky substance with white suspended particles)
.
First test would be in my mobile fully filtered aquosis quarantine system of 150 imp gallons with Stuart pressurised filtration the system consisting with small but normally adequate air pump.

The test fish a male kohaku of around 55cm water had had fish in it before and although clear was of normal organic load have not had and partials done on it. This was a normal run the rabbit experiment, either the myth was true in which case the fish would die or they were not and the fish would survive no other data points were to be considered apart form obviously the concentrations used and frequency.

Day 1 salt 1oz per gallon 0.6% and 10ml Formaldehyde 38% to every 150 gallons (approx 14.5 ppm) standard UK dose

Day 7 salt 1oz per gallon 0.6% and10ml Formaldehyde 38% to every 75 gallons ( approx 29 ppm) double UK dose

Day 10salt 1oz per gallon 0.6% and 10ml formaldehyde 38% to every 75 gallons (approx 29ppm) double UK dose

Note, The first dose was standard the salinity remains constant throughout experiment 6 clear days left between this dose and the next dose is a double the UK standard with no partials between doses , third and final dose a double dose with now only 2 clear days from the last double dose

The fish remained un-phased and healthy with no signs of distress during every stage of the test

This fish was removed healthy and well and took no further part in the experiment as if it were to die it was felt this would be from absurd levels of formaldehyde exposure not used in a garden koi pond, and not as a result of the combination with salt

Experiment 2

The same tank and equipment was used but this time three fish were the test subjects
1 x 55cm kojaku and two small fish around 26cm 1 x shiro utsuri 1 x variety unknown

Base line salinity for this experiment instead of being 0.6% was increased to 0.9% 1.5 ounces per gallon which is an extremely high level of salinity seldom used in the koi hobby but not entirely unheard of

Day 1 10 ml 38% formaldehyde to every 75 Gallons added
Day 4 10 ml 38% formaldehyde to every 75 gallons added along with 10ml 2% malachite green oxalate to 176 gallons
Day 5 10 ml 38% Formaldehyde to every 75 gallons added
Day 6 10ml 38% Formaldehyde to every 75 gallons added

Experiment over all fish survived

Observations
No signs of stress were observed during these trials

No losses of any kind were experienced 4 out 4 koi of varying sizes and condition survived

No filtration loss was experienced

One recorded abnormality, one fish out of the three in the last trial came out with cloudy opaque eyes (both) this was and is attributed to a known adverse effect with formaldehyde/formalin and although rare can sometimes occur and has nothing to do with the addition of salt, it happens in normal formaldehyde applications . cloudy eyes after formaldehyde is an event which usually rights itself in a few days as was indeed the fact with this fish , 7 days later eyes were crystal again.

Conclusion

As with all chemicals if you push hard enough there will be a situation where mortalities will start to occur this applies even with the solo therapeutic use of something as benign as salt even with this if you get silly fish will die. What I’m saying is if you really want to kill some fish you can take any preparation and push it beyond the point where it’s safe to use and witness the inevitability of mortalities but this proves nothing. But with this trial this was indeed the fact trying to find worse case scenario and push months of study into weeks.

I found it difficult to envisage a situation where the combined use of salt and formaldehyde would kill koi. If I was to get really silly and abusive with usage and dose rates if I had not already I suppose it would be possible. But given the lengths I went to with overdosing formaldehyde and salt and frequency of dosing I doubt upping the anti any more to see just where it would peak out would have gleaned nothing useful to the hobbyist given that Mr average ponder won’t get this insane with dosages and frequency of use

Do I advocate the use of salt and formaldehyde?

I will try and answer the question many of you will want answered now as best I can

In “normal” pond use I can find or see no way that using CH2O and NaCl together would result in koi mortalities that’s not to say that no such situation exists. I tried my hardest to find the breaking point using high dose rates that the hobbyist would not reach but could not discover its whereabouts, again that’s not to say one does not exist.

The long and short of it I’ve tested it to destruction and failed to kill any fish. Marine keepers report the use of formalin in a salinity of 3.5% with success. Similarly in the back of my mind is the thought where did this information originally come from? and for that reason itself you alone will have to be the judge based on the study. For myself I wont have the same fear ever again if I am salted and need to use Formaldehyde in a hurry.

Special Note for reference:

No other species other than koi carp Cyprinus carpio were involved in this test

The first trial was conducted under average organic loads

The second trial was conducted under lower organic loadings

17 ml to 150 UK gallons is = to the USA standard dose which is 25 ppm ( parts per million)

34 ml to 150 UK gallons is = to the USA double dose which is 50 ppm ( not recommended for more than 2 hours without salt in the equation By Doctor Eric Johnson))

20 ml to every 150 UK gallons is = to a UK double dose which is 29 ppm

10 ml to every 150 UK gallons is a UK standard dose which is 14.5 ppm

The authors herein are not making any recommendations in this abstract . The data presented here although tested extensively is not definitive, therefore its for information only.

This research is the property of Duncan Griffiths and is not to be copied, plagiarised, replicated elsewhere on the World Wide Web, email or in books or magazines unless permission is granted.

[bicolormoth]

given the results of this fascinating study, should this alter our opinion on the use of salt in our main ponds, say , an 'isotonic' level of 0.3%-0.6% to aid osmosis.
I have read & re-read various articles that argue for & against the inclusion of salt in koi ponds. the main argumant against is the possibility that it may hinder the use of various treatments.
if we accept that Formalin could now be removed from the list of affected treatments, would it be automatically safe to assume that MG&F would be okay with salt , and as (probably) the most commonly used pond treatment does this then push the salt/no salt argument further in favour of salt being used ?

i am going to have a fresh look at all the reasons for & against using salt to see what crops up, as i have always felt swayed towards YES, but have been put off by so many people telling me (or reading) to avoid it.
having done the calculation to give me a 0.3% = 1/2oz per gallon in my 5000g pond , i would need 2500 ounces, or 156lb which is 71kg of salt ! ... crikey , that's enough to put anyone off.

any thoughts on this anyone ?

Russell.

[Gazza]

Hi Russell,

Will it make me salt my pond....not a chance Koi are fresh water fish and not salt water fish and if you look on Duncan's ,main site you will see some articles on salt:

http://www.koiquest.co.uk/

[bicolormoth]

hmmm ... i read the articles Gazza they , and others, were the ones i was referring to in my post. i think the 'urge' to use salt comes from the very first pond i had, it was already in my garden when i bought the house but was woefully underfiltered , so off i went to the koi place and bought a multibay etc, and came away with a sack of PDV salt and dosage instructions. Once i moved to a bigger pond & a Qt set-up i have reserved the salt for the QT, but the 'urge' is still there. just a little niggle really. its more about no really knowing for sure EXACTLY which is best. i feel i am probably doing it right at the moment but not totally convinced. put it this way, i don't think i could advise someone else which is best, i would have to sit on the fence and admit that i don't really know.

Russell.

[tomy2ponds]

Hi Duncan very interesting results I don't salt my pond but if I had to say due to NPS and then needed to use Formalin I would now be happy to do so.Your hard work on this is really appreciated as you said where did the myth come form who knows but it is well and truly busted now thanks to you.
In answer to Russel's question re salt in a pond not for me for the reasons Gazza has said Koi are fresh water fish plain and simple.

[dagsteve]

great stuff,im knackered from the read
im not about to bung salt in the pond,but at least salt could be added to a quarantine.
and futher treatments could be undertaken if necessary without the worry of reducing the salt content
thanks