3 deaths in 24 hours - EI / EasyCarbo related???

[Packers]

I've changed a few things in my tank in the last couple of weeks. I have a fairly low-tech 95l tank with yeast based CO2 system that has been running for 9 months or so. I've been reading a lot on here and decided to try to improve my tank so I am about to move and rescape my tanks and I started a thread in the journal section. I have also started dosing EasyCarbo at recommended doses on the bottle, and Aquarium Plant Food UK EI starter kit at currently about half the recommended dose (I thought I may need to use less as I don't have pressurised CO2 or high lighting). The only other thing that has changed on my tank is that I have added a koralia powerhead.

I am using London tapwater (with addition of stuff to remove chlorine/chloramine) and have been for the last year. I have had occasional deaths due to ich and dropsy when the tank was newer and more unstable, but I haven't had any fish problems recently - until the last 24 hours when I found a celestial pearl danio/galaxy rasbora and a cherry shrimp lying on the substrate, and one of my celebes rainbowfish seems to have disappeared overnight (I presume it has died and been eaten by the others?). My test kit (API) shows no ammonia or nitrites. Nitrates are 40ppm (that is what is coming out of the tap at the moment). I also think one of my Otos and another celebes rainbowfish look at bit off colour. As I can't think of anything that could have caused a sudden death spree in my tank other than the addition of EasyCarbo and EI dosing (which may be too high for my plant load / set up). I have done a water change this evening, and I don't think I will dose anything tomorrow. I have also turned off the powerhead as I wondered if the sudden increase in flow could have stressed the fish???

Does anyone have any other ideas / suggestions / advice?

 

[Iain Sutherland]

It won't be EI as nutrient supplements won't cause I'll effect unless you over do it to a ridiculous level, easy carbo could be you culprit, check the dosing instructions again as it is easy to over do it in small tanks, it's also extremely unlikely your power head had anything to do with it.
With anonymous deaths most people run daily 30-50% water changes for a week, if you do this also shorten your lighting period so algae doesn't pop up due to less nutrients for the plants.
Unfortunately sometimes it happens without a clear explanation, my friend lost 13 fish in as many weeks, ran his water through a mass-spectrometer (his job) with no cause there or signs of disease....
I could be something as simply as stress due to a new routine and the older fish just couldnt manage it...

 

[Iain Sutherland]

Also how/what are your stocking levels??

 

[Packers]

I'm at about 80% stocking at the moment, which has remained the same over the last 9 months. I was planning to rearrange my tanks over the weekend and split the fish across two tanks anyway, but I'm not sure if I should hold off on that now.

 

[W1368]

As you have just begun EI, is this also the first time you are changing 50% of the water? Also when was your last large water change in relation to the fish deaths?

I had witnessed my fish becoming very stressed when I first started large water changes (after many years of only 10-20% changes a week). If you are not already I would recommend making sure that the new water is of similar temprature before pouring into the tank, and that it is poured slowley.

I fill a couple of jerry cans a day or two before a w/c and allow to warm to room temprature + add water conditioner for safe measures.

As your tank is smaller, the sudden changes in water chemisty may have a higher risk, especially if you fish are not used to it.

You may also want to double check the C02 in case this has run its course. I once used a yeast based bottle, it had run out long before I had noticed and also experieinced fish deaths - I've used pressurized ever since.

 

[Packers]

I've come home to find another dead celebes rainbowfish, and the gills of several others are quite red.

This isn't the first time I've done big water changes, but I have noticed that the fish are more stressed when I change more water. I also often leave the water overnight with a heater in the bucket (my house is very cold, so leaving the water without a heater means that the water is too cold to add to the tank).

The CO2 is ok, I changed one bottle at the weekend (I change one every week, alternating which one I change so each bottle runs for 2 weeks - I've done this for months with no previous adverse effects). My drop checker is constantly green.

After the reassurance over EI I started dosing again today (trace mix, 50% of the standard dose) and EasyCarbo 1.6ml for about 80l water volume (after taking account of substrate/hardscape volume), which is the recommendation on the bottle. I use a 2.5ml syringe to measure out the amounts, so it is fairly accurate. I didn't dose any the day before as I was worried about these things causing the deaths.

I'm going to do some more reading on fish illnesses and do another water change tonight. I realise that I may not work out what is causing these deaths, but if anyone has any further advice/ideas, I am really grateful for your help.

Thank you to everyone who has offered advice.

 

[mark4785]

If your ammonia and nitrite levels are stable, you don't need to be doing water changes. As someone has already mentioned, have you changed the volume and/or frequency of your water changes? If so, the KH and GH (and possibly ph) values of the aquarium water will be hugely differential to your tap water's KH and GH so increasing the amount of aquarium water you replace more frequently could be a high source of stress on the fish's skin and gills.

Unless you have seen gasping at the surface or fish gasping at the substrate level in one particular area without any interest in food, its unlikely to be the Easycarbo causing the deaths although it could be contributing.

 

[dw1305]

Hi all,
Red gills is usually a sign of ammonia, even though you can't read any with your test kit doesn't mean it isn't there.
It may be that you water company is doing some water mains work and have added a large dose of chloramine to your water.

cheers Darrel