Mystery Deaths After Water Change In 35L Tank

[daizeUK]

My fish are showing some kind of shock reaction to water changes in my 35L tank. The tank contains young platies who are growing out, aged about 1-3 months.

Every week I give them a 50% water change with temperature matched water (using a mix of water from hot & cold taps). I dechlorinate in the bucket using Seachem Prime. I always double dose my Seachem Prime for all my tanks because the water supply contains lots of chloramines.

Afterwards the young platies in my 35L always go into hiding, huddled in the corner at the bottom of the tank or lying on top of the filter. They often stay that way for a full 24 hours before swimming around normally again. The fish in my other tanks do not show this reaction after a water change, including more young platies in my 64L tank.

This time I left the 35L tank for a few days longer than usual before it got a water change and the effect was even worse than usual. All the young platies were up at the surface keeping still for about 2 days. They appeared weak but not gulping or gasping. Then they started to swim about a bit but one died. Another 24 hours later and they are swimming about a bit more but the smallest one was too weak and getting blown around the tank. I've currently got him in a container of still water to let him rest. I don't think he's going to make it.


Stats across all tanks: Ammonia 0.0, nitrite 0.0, nitrate 40ppm.
Tap results are Ammonia 0.0, nitrite 0.0, nitrate 30ppm.

pH is 7.4 out of the tap which rises to 8.2 in both my 35L and 64L tanks. I wondered if it might be pH shock but then I would expect the same reaction in my 64L tank too.

One difference is that I use a hose to fill my 64L tank and a bucket for my 35L. I have used buckets on my 64L before without problems though.

I'm stumped, I can't think what else the problem could be.

All I can think is that I need to do smaller water changes on my 35L to lessen the shock, but I don't understand what is causing it. Any ideas?

 

[noobgamers]

i think smaller water changes will help on a tank that size 25% a week should be fine if the nitrate keeps going up though increase the water chaange amount if you have to do this try 5% at a time

 

[KirkyArcher]

Why double dose the Prime at all? Surely there is no need when using a bucket of treated water for your water changes with an established tank and filter, next water change I'd try just using the recommended dose and see how your fish react. If I recall correctly Seachem advise to half dose Prime if Ammonia or Chlorine levels are low!

 

[TwoTankAmin]

What else, if anything, are you dosing in the tank? Are you by any chance adding Excel?

 

[daizeUK]

i think smaller water changes will help on a tank that size 25% a week should be fine if the nitrate keeps going up though increase the water chaange amount if you have to do this try 5% at a time

Thanks for the advice - sounds like a good idea!

Why double dose the Prime at all? Surely there is no need when using a bucket of treated water for your water changes with an established tank and filter, next water change I'd try just using the recommended dose and see how your fish react. If I recall correctly Seachem advise to half dose Prime if Ammonia or Chlorine levels are low!

The Prime states "For exceptionally high chloramine concentrations, a double dose may be used safely".
I got into the habit of double dosing it after the Tetra strip tests indicated I still had chlorine present after a single dose. I can try a single dose for the next WC to find out if Prime is the culprit!

What else, if anything, are you dosing in the tank? Are you by any chance adding Excel?

Nothing in my 35L. I am adding EasyCarbo to my 64L.

 

[TwoTankAmin]

Well that shoots down that idea.
 

You are correct that you should not dose Prime together with Flourish Excel because they are reducing agents. If you are cycling you can add Prime every 48 hours; no need to add it daily. It is better to be safe and not use them both; especially at the higher doses.

from http/www.seachem.com/support/forums/showthread.php?t=7007
 
But I would still give a shot at not double dosing the Prime and see what happens.

 

[noobgamers]

 

i think smaller water changes will help on a tank that size 25% a week should be fine if the nitrate keeps going up though increase the water chaange amount if you have to do this try 5% at a time

Thanks for the advice - sounds like a good idea!

Why double dose the Prime at all? Surely there is no need when using a bucket of treated water for your water changes with an established tank and filter, next water change I'd try just using the recommended dose and see how your fish react. If I recall correctly Seachem advise to half dose Prime if Ammonia or Chlorine levels are low!

The Prime states "For exceptionally high chloramine concentrations, a double dose may be used safely".
I got into the habit of double dosing it after the Tetra strip tests indicated I still had chlorine present after a single dose. I can try a single dose for the next WC to find out if Prime is the culprit!

What else, if anything, are you dosing in the tank? Are you by any chance adding Excel?

Nothing in my 35L. I am adding EasyCarbo to my 64L.
 

no problems its what i joined the forums for is to give advise

 

[daizeUK]

Well that shoots down that idea.

You are correct that you should not dose Prime together with Flourish Excel because they are reducing agents. If you are cycling you can add Prime every 48 hours; no need to add it daily. It is better to be safe and not use them both; especially at the higher doses.

from http/www.seachem.com/support/forums/showthread.php?t=7007

Cheers anyway mate, that's interesting info. I wonder if EasyCarbo has the same effect as Excel. I see no signs of discomfort in that tank though, perhaps the water is so highly oxygenated after being sprayed out of the hose it doesn't matter?

 

[KirkyArcher]

I'd be doubting the readings on the test strips indicating Chlorine (as you know test strips are notoriously unreliable) , I have just read a few posts on other forums, one suggested that a tank that hadn't  had any water changes suddenly showed that it had high chlorine readings.  If Seachem say that double dosing for exceptionally high chloramines is recommended  what does it say about Chlorine after all that's what your strips detected?

 

[coolie]

Yes, I concur that those chlorine strips don't work. I wonder how they even made it off the drawing board.

 

[daizeUK]

I've had firm belief for the past year that my water supply is high in chloramines but I can't find where I got that idea from!  My water supplier doesn't mention it on their website (and they're good at providing very thorough water quality info). I was thoroughly convinced but now I don't even know why...

  Perhaps again I've been putting too much faith in test results.
 
I'm now uneasy that I've been following instructions to double dose Prime for the FULL CAPACITY of my 64L and 120L tanks because I don't use buckets for them.  Right now I'm doing it TWICE per week on my 120L tank on advice to combat algae... I think I'd better stop pouring so much Prime into my other tanks too, just in case!

 

[KirkyArcher]

With seachem "prime" and seachem "safe" it's the recommended way of dosing for the tank with hose refilling (for the entire tanks volume of water), double dosing for the entire volume is overkill quite literally

 always remembering that about 15% of the measured tanks dimensions volume will be lost to substrate plants ornaments etc. With regular water conditioners you just dose for the amount of water you're replacing. To be quite honest I can't see the point of using prime other than in emergencies and to handle abnormal tank parameters, all of which should be controlled by decent filtration and tank housekeeping.

 

[daizeUK]

To be quite honest I can't see the point of using prime other than in emergencies and to handle abnormal tank parameters, all of which should be controlled by decent filtration and tank housekeeping.

Do you recommend a different dechlorinator? I use Prime mainly because it's so cost effective, not so much for the extras it claims to provide.

 

[KirkyArcher]

I use Pond Medic Dechlora by Kockney Koi, "Removes all chloramines (chlorine compounds) and harmful toxins from tap water" for about £15 you get a litre of the stuff and that's enough to treat 15,000 gallons (yes honestly 15,000 Gallons = 68,000 litres) as it's super concentrated, I dilute 55 ml out of the bottle with 945 ml of Deionized water so that I can dose 5ml for every 20 litres of water, not going to run out of the stuff anytime soon, should last me about 24 years

 

[daizeUK]

Nice one! I remember doing a dechlorinator price comparison over a year ago when I was trying to work out which product to use. I think API Tap Water Conditioner came top for sheer value for money. At the time I thought that Prime was a better choice since it could detoxify any ammonia created by the removal of chloramines which I was convinced I had.

Anyway, I've still got a full massive bottle of the stuff so I'll be sticking with Prime for a while yet to come!

In the meantime I'll cut back to recommended single dosage and report back in a couple of weeks. Thanks for the help!