Michelle.g Posted July 28, 2008 Report Share Posted July 28, 2008 I have been keeping fish for a few years, and my partner recently got inspired by a nice tank he saw and bought his own tank. It's a 34L AquaOne tank. We had issues with heating when it was first set up so we got a new heater and it seemed like it was all ok. I'm pretty sure we did everything right, used ceramic noodles from one of my other tanks, washed all equipment well etc. The tank has some plants and dark fine gravel. The heater and thermometer were placed in the recommended locations in the tank (opposite sides of the tank). We put 6 swift rasboras into the tank on Sunday and got up this morning to find 5 of the 6 dead. I'm confident that they were healthy fish when we got them from the store and I have bought lots of great fish from the same place before. We have no idea what happened. The temperature was at 26.3 degrees C this morning. Last night I watched the temperature carefully and according to an AquaOne Digital thermometer the temperature varied between about 27.5 and 26.5 degrees. Does this seem like too much variation? Is this too hot for the rasboras? I was told around 27 should be ok. Could the thermometer be inaccurate? The other thing is the heater had to be set at 30 degrees C to keep it that warm. Does this seem extreme? We are currently using a 100W AquaOne heater as we found that 55W wasn't enough. The rasboras seemed to hide from the current, could this be what upset them? Sorry for all the questions. My partner really liked the rasboras, so if someone has some suggestions of what was wrong so we can correct it he might like to get some more for the one lonely rasbora we still have. Quote Link to comment Share on other sites More sharing options...
Cricketman Posted July 29, 2008 Report Share Posted July 29, 2008 digital thermometers are known to be in-accurate, well, from my experience, and thefact that you had to set teh heater to 30 screams to me that it may be the thermometer you have that is upsetting the balance. also how long did you wait before adding the fish? Quote Link to comment Share on other sites More sharing options...
tHEcONCH Posted July 29, 2008 Report Share Posted July 29, 2008 34 litres isn't very big - and the smaller the tank, the greater the temperature will swing around - that said, you've got a big enough heater to keep it warm unless your house is particularly cold. Ignore the '30' on your heater - those marking are virtually meaningless unless you can calibrate the display with actual tank temperature - just set it to where the tank temperature is maintained at 26-27 degrees (which it sounds like you have already). You also need to test for Ammonia etc. to make sure your tank is cycled - that is probably what killed your rasboras. Quote Link to comment Share on other sites More sharing options...
Dracoz Posted July 29, 2008 Report Share Posted July 29, 2008 Did you test your water? Ph level? Ph shocked ..may be Quote Link to comment Share on other sites More sharing options...
Caryl Posted July 29, 2008 Report Share Posted July 29, 2008 I did a search to find out what a swift rasbora was. Discovered they are the Hengelis. I do wish they would stop coming up with different names! :evil: These are great fish and I have them myself. They are also very suitable for the small tank you have. Did you check the ph etc of the water they came from before you acclimated them to the new tank? The temperature will swing a few degrees and this is normal and not a problem. Rasboras generally like a current, their torpedo shape makes them suited to faster moving water. Quote Link to comment Share on other sites More sharing options...
whetu Posted July 29, 2008 Report Share Posted July 29, 2008 I second (third?) the pH suggestion. There aren't many things that will kill a fish that fast. Take a sample of the tank water to the shop where you bought the fish and ask them to test it, then compare it with the shop's water. A pH difference shouldn't prevent you from keeping these fish - it just means you have to acclimatise them VERY slowly. Please let us know what the results of your water test are. Quote Link to comment Share on other sites More sharing options...
Michelle.g Posted July 29, 2008 Author Report Share Posted July 29, 2008 Thanks to everyone for your thoughts. I'm going to borrow an alcohol thermometer and a mercury thermometer to check the temperature tomorrow. So hopefully that will tell me whether there is an issue with the digital thermometer. We are hoping the heating is not the issue. I did a quick check of the water with those "API test strips" and found the pH to be around 7 and Nitrite and nitrate look to be close to 0, but I know these aren't very accurate so will try to take some water to be checked at the shop. When the tank was set up we put in ceramic noodles from one of my already cycled filters and some of the tank water as well so I had hoped this would help. Are swift/Hengelis rasboras pretty hardy fish? What do people think is the best way to slowly acclimate the fish to a new aquarium? And how big a change in pH would be a problem for the fish? Quote Link to comment Share on other sites More sharing options...
whetu Posted July 29, 2008 Report Share Posted July 29, 2008 hmmmm... well if the pH is around 7.0 then I can't see that being the problem after all... And the addition of media from the other tank should mean you've minimised any ammonia spike... You're going to double-check your temperature... And I thought rasboras were pretty hardy... Sorry, I think I've run out of ideas! Quote Link to comment Share on other sites More sharing options...
SpidersWeb Posted July 29, 2008 Report Share Posted July 29, 2008 NB: digital thermometers for fish tanks are inaccurate, but the 1 degrees variation WILL be accurate. What's not accurate is that they're not calibrated, e.g. 25C on one might be 26C on another. 1C is normal, the heater turns on at x degrees, and off at x+1 degrees. This really really annoys me, hence my temp controller project, but it is normal for most fish tanks. Nitrite is something else to watch as it can result in overnight sudden deaths as well, but sounds unlikely in your case if you only just put the fish in. Quote Link to comment Share on other sites More sharing options...
Michelle.g Posted July 30, 2008 Author Report Share Posted July 30, 2008 I just checked the temperature in the tank. The digital thermometer is currently reading 26.0 degrees C and the alcohol thermometer is reading almost exactly 29 degrees C. We have been watching both thermometers for a while now and the alcohol thermometer is always reading about 3 degrees hotter. The alcohol thermometer should be very accurate. I'm shocked to find how different the readings are! The tank got to a maximum of about 28 degrees C (according to the digital thermometer) when the rasboras were in the tank, so if this was actually 31 degrees C could this have killed the rasboras? I'm quite upset to find that the thermometer is so inaccurate. The packaging for the thermometer states that it is accurate +/- 1 degree C. We may have killed the rasboras. Also we replaced a heater because we thought it wasn't powerful enough and maybe it was ok. What can I do? Quote Link to comment Share on other sites More sharing options...
spoon Posted July 30, 2008 Report Share Posted July 30, 2008 r the thermometers right next 2 each other as he temp can vary around the tank Quote Link to comment Share on other sites More sharing options...
Michelle.g Posted July 30, 2008 Author Report Share Posted July 30, 2008 r the thermometers right next 2 each other as he temp can vary around the tank Yes, they are right next to each other. We have also tried moving the thermometer to different parts of the tank and the temperature is very similar throughout the tank. Quote Link to comment Share on other sites More sharing options...
SpidersWeb Posted July 30, 2008 Report Share Posted July 30, 2008 r the thermometers right next 2 each other as he temp can vary around the tank Not by 3 degrees! It's really annoying this temp reading problem. There is no quality control and the advertising outright lies. It should be taken to the commerce commission and all stock thrown out. I was recommended by other fishkeepers to buy 3 digitals. Return the 1 or 2 with rediculous readings. Seems to be on average 1/3 are miles out. I got an AquaOne digital a few weeks ago, and part of the LCD wasn't even working, its pathetic and unacceptable. I say unacceptable because people say 'you get what you pay for' BUT there isn't anything else in pet stores. They just stock the cheapest thing that looks good. The stick on ones aren't better either. One of mine is out by about 3 degrees celsius as well. Quote Link to comment Share on other sites More sharing options...
Dracoz Posted July 31, 2008 Report Share Posted July 31, 2008 Lack of oxygen in the water can kill your fish very quickly also Quote Link to comment Share on other sites More sharing options...
whetu Posted July 31, 2008 Report Share Posted July 31, 2008 When you select a thermometer at the pet shop, take them all off the rack and line them up in order of the temperature they are currently showing. Then buy the middle one. Also, use the thermometer to judge the water temperature, not the thermostat on the heater. I have NEVER had a heater that is even vaguely accurate when set to a certain temperature. Quote Link to comment Share on other sites More sharing options...
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