Alan Posted November 25, 2004 Report Share Posted November 25, 2004 Here are the facts as I know them. A friend of mine was having problems with his tank going cloudy, so he did a 50% water change using Water-ager in the new water. Everything seemed ok, until he noticed his neons had started to die. Three before work and on arrival home quite a few more, until only four of the school of twenty were dead. ALL were egg laden females, and an autopsy showed them to have very red gills. Water conditions are fine, no ammonia, nitrate, or nitrite. pH was 7.6. Water was so good the Pristillas decided to do their thing and spawned all thru the tank. No sign of Neon Tetra deasease, anyway, that wouldn't knock out that many in such a short time. SO, what do you reacon?? Any ideas?? Other than the fact that I think somehow the new water was toxic to the neons, but strange also, that it was the females that died. Open for discussion. By the way, he may be in tonight with a friend, so get ready with the buckets of water to chuck over them. Alan 104 Quote Link to comment Share on other sites More sharing options...
Lucid Posted November 25, 2004 Report Share Posted November 25, 2004 Any particular reason for it being in the trade and exchange section Alan, Are you trying to sell the problem that caused the death or is there a secret plot yet to be revealed. B Quote Link to comment Share on other sites More sharing options...
cees Posted November 25, 2004 Report Share Posted November 25, 2004 moved :-) Quote Link to comment Share on other sites More sharing options...
Caryl Posted November 25, 2004 Report Share Posted November 25, 2004 I presume you mean only 4 of 20 survived and all males? I can only think of something in the water that affected the females who were more susceptible being pregnant. Other than that I draw a blank. :roll: Any other fish in the tank apart from the pristellas? Seems odd it didn't affect the females of them though. Quote Link to comment Share on other sites More sharing options...
Melanotaenia Posted November 27, 2004 Report Share Posted November 27, 2004 Alan, what is your friend's tap water like? Hard I suspect... AFTER the water change it was pH 7.6 correct? This is not good for the neons and in fact most tetras who prefer soft acidic water. Pristella (or X-ray) tetras (Pristella maxillaris) are an exception living in the lower reaches of the amazon and orinocco rivers and therefore liking more alkaline harder water. 4/20 of the neons survived and apparently male? This I doubt - the chance that only 4/20 of the originals were male is pretty small. I don't think sex was a factor. The gills were red implying some kind of resipration problem. The water was cloudy in the first place indicating pre-existing water quality issues. My theory is that by doing a large water change with harder alkaline water increased the pH too fast which also changed the ratio of dissolved O2/CO2 thus stressing out the neons causing death. The pristellas spawned because they prefer the new harder water. To test my theory get your friend to do a KH test on his tap water. Also what was in the water-ager?? Richard Quote Link to comment Share on other sites More sharing options...
Melanotaenia Posted November 29, 2004 Report Share Posted November 29, 2004 I had some further thoughts that I thought were worth sharing.. :lol: Firstly it is the when the monsoon rains come that usually signals breeding season. This stirs up the rivers and mixing the sediment causing more harder alkaline water...which is why (if the tap water was hard) the pristellas spawned.. However neons should be able to *survive* up to pH 8, so maybe sex was a factor. :-? It is entirely possible that 16/20 were female. I got thinking about human females and how in the last months of pregnancy lots of things can (and do) go wrong...and they also particulary don't like heat...soooo by increasing the pH we will be increasing conc of O2 and lowering CO2, which will tend to *speed up* fish metabolism (the gills were red indicating highly oxygenated blood) and so the preg females couldn't keep up with the metabolic changes (heat) and so died an 'over-speeded' tetra!! All this hinges on the tap water being hard...otherwise I'm back to square one... Quote Link to comment Share on other sites More sharing options...
Alan Posted November 29, 2004 Author Report Share Posted November 29, 2004 Melanotaenia, thanks for your thoughts on this problem. The water we have in Ohope, is the same as we have in Whakatane. This is taken from our river, treated, and made "slightly" alkaline so as it is not"aggressive" to the reticulation system (pipes). The river rises in the ranges to our south, which are in-general, forest clad, finally meandering through farmland to the sea. This is is not a limestone area, so the water, before treatment is on the soft side. I don't know where my figures from the treatment station are, so I cannot give you the exact target they aim for. Maybe EJ, if he reads this, could give us a run-down of the water parameters, as he takes a close interest in this for his planted tank. Alan 104 Quote Link to comment Share on other sites More sharing options...
Luke* Posted November 29, 2004 Report Share Posted November 29, 2004 (First of all i agree with Melanotaenia, good ideas, except I think most of NZ's water is soft, doesn't mean to say the O2/CO2/alkaline exchange still didn't occur, my tap here is 0-1DH but is 7.8+pH). How long had the neons been in there? I'm thinking ammonia. When I had a bunch of guppies in an uncycled tank once pretty much only the pregnant females died. The males were left largley unscathed. Not sure why this was but thought it would be worth sharing. Perhaps ammonia attacks and irritates the gills? Quote Link to comment Share on other sites More sharing options...
Melanotaenia Posted November 30, 2004 Report Share Posted November 30, 2004 Hmmm the plot thickens... It would be good to see the test results but in the meantime I agree...it's unlikely Ohope water is hard....so either it was just a high pH effect (which like luke* said would still have caused the dec CO2/inc O2 effect) :-? or I have another idea... :lol: the river does go through farmland yes? and its dairy you have up there? Which is renowned for high chemical use. So maybe it was just a farm chemical toxin and the fact that females were (mainly?)effected makes me think it could have been some bovine hormone residue. It only takes minute amounts of hormone to have big effects.. especially is something like a small preg neon.. If it was though we'd never know... Quote Link to comment Share on other sites More sharing options...
herefishiefishie Posted November 30, 2004 Report Share Posted November 30, 2004 Where I work is in Brisbane. Brisbane has 2 sources of water. I work close to the border. The majority have good water for fish, slighlt alkaline(ph) & moderate dh hardness. The miniority of Brissie has water that is about 7.5 to 7.8 ph, & very little dh. What happens is that over a period of time the ph drops. (as dh acts as a buffer) We get this problem often. If your mate hasn't changed the water for 3 weeks or more his water ph I bet would of been acidic. :-? 50% water change has shocked your neons(red gills) as water is now alkaline. The other tetras have gone sweet, rainy season lets breed. There is a product here that is good for soft water, conditioning salt, keeps ph stable. The powders are useless. :evil: Frenchy Quote Link to comment Share on other sites More sharing options...
Alan Posted November 30, 2004 Author Report Share Posted November 30, 2004 I think I'd agree with a lot of things that have been said. But the dairy runoff doesn't affect me so I don't think it should over the hill. I'd go along with the water change theory, a pH shock probably, and somethings just, IMHO, rule others out, ie, if the pristillas spawn then the water was ok for them it should have been okers for the neons. One thing we all know for sure tho, is something happened to those 16 female neons that didn't agree with them. Thanks for you help. Now if only Scott would get a puta, he would be able to see what conclusions we have come to. Alan 104 Quote Link to comment Share on other sites More sharing options...
Warren Posted November 30, 2004 Report Share Posted November 30, 2004 Also, if there was ammonia present and the pH was below 7 before the waterchange it would have been ammonium which is much less toxic. If the pH went over 7 after the waterchange the ammonium will change to ammonia. The toxicity of the ammonia gets 10x worse for every pH point above 7 (10x at pH=8, 100x at pH=9, 1000x at pH=10 etc). Maybe the Neon’s aren't ammonia tolerant and the other tetra's are. Many fish never develop a tolerance to ammonia as their natural environment never has it present. These are usually the first fish to die when an ammonia spike occurs. Tetra's natural environment is acidic therefore no ammonia... Maybe these Neon’s were wild-caught and the other tetra's were captive-bred. Wild-caught fish are usually more sensitive. Quote Link to comment Share on other sites More sharing options...
breakaway Posted November 30, 2004 Report Share Posted November 30, 2004 Speaking of neons, most neons I got from HFF mt. roskill are very sensitive. I was told when I first started the hobby that they were very hardy fish, but once I bought them, they started dropping like flies. One of them died because of a cyst on the tail. The others just kept dying. Then I bought some more. They dropped like flies too. Must be a bad batch of fish or something. Quote Link to comment Share on other sites More sharing options...
herefishiefishie Posted December 1, 2004 Report Share Posted December 1, 2004 if the pristillas spawn then the water was ok for them it should have been okers for the neons. You may think that, but no. Neons are very sensitive little buggers. Therefore changes in water will kill these guys..& girls: ph,nitrites,temp..... That is why shops never(shouldn't) :roll: sell them people who are starting a new tank. Frenchy Quote Link to comment Share on other sites More sharing options...
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