Dose rate check please.

[Dandj]

We to have sufferred dreadfully after dosing with FMG.......

Interestingly research - after the event- (hindsight is a wondorous thing!) reveals longstanding issues with malachite....
From 1 of the 1st hits..

"Add 100 ml of Proform C for every 1000 gallons of water to be treated. This dosage level produces 0.05 ppm of Malachite Green and 15 ppm (or mg/liter) of Formalin."

In the aquatic toxicity literature for pesticides, I find the 96 hour (4 day) LC50 (Lethal concentration that kills half the fish) for Malachite Green for carp is 0.1 ppm, or twice the actual dose labeled on a bottle of Proform C. The bottle label dose, however, is for a full dose for three successive days, or a total of 1.5 ppm Malachite Green if practiced at bottle label conditions.

So some folks do experience deaths when using Proform C at bottle label conditions. No wonder, since the dose is 50% higher than the 4 day LC50 for carp.

I don't use Proform C as the bottle labels. I use a full dose, wait 5 days, dose again, wait 5 days, dose again. This gives the Malachite Green a chance to be decomposed in the pond environment before the next dose.

Maybe the folks who throught they had problems with Proform C and salt just were seeing Malachite Green overdoses when using Proform C at bottle label conditions.

Comments, discussion? "


so I got hubby to check at work:

"Done a quick search curtsey of our aquatic ecotoxicologists and the article you posted to me may well be right. Couldn’t find anything that approached a reliable LC50 for carp, but there was some information in carp and lots of published LC50 s for other species. It has a log Koc of 0.6 l/mg so that means that the activated carbon will also pull it out of solution but it does not biodegrade or have any abiotic degradation pathways."


So basically in sunless weather without your UV running the malachite accumulates so each dose pushes the koi into the toxicity range ....unless you do massive water changes.

Our koi are looking 100% happier in a vat whilst we empty and refill the pond whilst trying to keep the filter alive by pumping across water from the vat to the filter..... however many will never be the same, 1 problem 3 have is downward turning eyes, these look awful but at least they are swimming and cruising in the vat, and the redness to the skin is settling down.
As you will see from the time this is written I am not getting much sleep! just been out to check water conditions in the vat as we have a lot of koi in 1500 gallons with just a protein skimmer running on it!

I for 1 will never use malachite again.

[Spalders]

As Jane says, hindsight is a wonderful thing.
Anyone who might care to undertake some further reading need only enter 'toxicological effects of malachite green' in Google (other browsers exist) and you will be able to access some interesting scientific articles about the effects of the chemical on fish.
Dom.

[bigmel]

Hi Dom

Found the thread mate , hope the koi have recovered .

just some thoughts going through my head regarding whitespot , never had it in the pond but before i kept koi i kept tropicals ....and lots of them in a fish house (converted garage ) .

I had whitespot several times over the years after buying new stock , if i didn,t catch it early enough which was by visual inspection not scrapes (salt size grains on the fish and flashing) i could have high loses .
I,m just thinking maybe the whitespot was in an advanced stage so some deaths were on the cards ?


Haveing said that at tropical temps and small tropical fish in low water volumes i would expect this but koi are more hardy , in lower temps and more water volume so perhaps i,m way off the mark .
Also any bigger tropicals i had did recover from whitespot if i spotted it early enough which is easy in a fish tank but near impossible by eye in a pond .

Just thinking out loud and learning .

[Spalders]

Hi all,

Just thought I would close off this thread with a final update on what happened.

In the end I lost seven fish up to 55 cm - including a tancho showa, a gin rin showa, two shiro utsuri, a couple of ogons and a gin rin chagoi. On the worst day I lost 4 in 24 hours. As a person I don't really do emotions but it was really hard work to keep going at times; I do love a challenge though and I considered it a huge challenge to save my koi.

Had it not been for the help of fellow koi keepers I expect i would have lost a lot more; despite flushing huge volumes of water out of the pond we decided in the end to remove the fish to a holding tank and dump the water completely, jet wash the pond and refill it with fresh water. During this exercise we found quite a lot of the equipment stained blue (from the MG presumably) even after the massive water changes that had been completed previously.

It may sound a little odd to say that I am delighted to have 11 out of 18 survivors and can now move on with koi keeping. Despite the pond looking devoid of fish at times I'm in no rush to restock although I have purchased one new nisai chagoi which is in quarantine for another few weeks yet, and some tosai to grow on for next year.

I have fitted a Dura 10 + ASHP and am maintaining 23 degrees during the recovery process; I have also rebuilt my skimmer line to incorporate a Clarity unit which has hugely improved the appearance of the water (I always thought it was good anyway as I have OCD keeping it clean!).

Some of the survivors exhibited no symptoms whatsoever which was quite extraordinary in the circumstances. The koi that died exhibited a variety of symptoms - one or two had quite badly 'burned' gills whilst others seemed to suffer organ failure - they would be OK with salt at 0.3 but if this was diluted out with water changes they would immediately start struggling again. Because I had to maintain a constant flush of fresh water on the quarantine facility I could not maintain the salt level; I'm sure those fish would have died anyway due to severely weakened systems.

Some of those that died and some that survived had burns to the edges of their fins - in all but one case those koi affected recovered quite quickly. The one that did not recover quickly became infected and I have been treating for fin rot; this resulted in the amputation of the first 4 rays of the right pectoral fin at the base of the joint.

This fish and one other were given a course of baytril and the usual topical treatments -- roccal, Duncan's mercurochrome, Lock & Seal and orahesive. The amputee, a beautiful and unusual chocolate ochibe from Cuttlebrook, now named Arfur (half a pec) is back to her old self - hungry and competing for food with the others.

This koi was inspected yesterday and returned to the pond with no further treatment as I am very happy with its progress after quite major surgery.

I also have a gin rin ochibe which I have been treating for a bacterial infection following what initially appeared to be a simple raised scale. Ten days after a course of baytril and the topical treatments stopped she now looks like this: -

Gin Rin Ochibe - infection on the mend.jpg (89.38 KiB) Viewed 4813 times

I have removed quite a few scales but the scale pockets are in tact, new skin is forming and the area looks a lot less angry than before; although she is not out of the woods yet I think I'm getting there. Yesterday I gave the area a general clean and topical treatment as above. I'll inspect her regularly just to be sure continues to make good progress.

I'll never know for sure what happened - there are several possible explanations some of which are covered elsewhere on this thread. I see no benefit in dwelling on the past but I have learned many lessons over the last couple of months which will certainly help me in future.

If you have got this far in the thread, thanks for reading; I really hope you don't ever have to go through with your koi what I have been through this summer with mine.

Dom.

[Mattybkic]

Hi Dom

Thanks for the update. I'm glad things have now settled for you and you can now move on.

Best of luck and look forward to catching up with you for a chin wag at either Cuttlebrooks or Coldwater soemtime in the near future.

Matthew

[Spalders]

Hi Matthew

I was at the show yesterday....

Going to be at the MKA show and also the Kennet Valley if you are going?

Dom.