Daily Fluctuation of Water Temps

[Rob0504]

Our new 40 gallon tank that is being cycled with fish, lots of fish (per advise of fish store), is six weeks old. We have had no heater since we are in the summer months. The temps range from 78-81 in the day and reaches lows between 77-78 by morning.

Also, I use a Python to do daily water changes and do not match water temp to the exact temp in the tank; maybe off 1-3 degrees.

How does this effect the fish or tank, if it does?

Thanks!

 

[MattAquaBio]

Fluctuating water temperatures lower your fishes immune system. A gradual drop in temperature every now and then isnt that bad, (after all there is a night in the wild too right?) but if you let the temperature fluctuate IMO it will lead to ich or another disease.
The water changes i'm not sure about, i never bother to like use a thermometer to get the temp of water i'm putting in. But i get it as close as possible. I personally dont believe that water changes would be detrimental.
Good luck.
hth.

 

[joannde]

On the water changes, it depends upon the amt of water being replaced and the temperature difference of the water. If it is a 10% change it will have a lesser effect on the overall water temperature. If's it a larger change and the temperature varies greatly you can actually put your fish into temperature shock (which is one of the methods of euthanasia).

 

[DagothUr]

From my experience anything below a 10% change it doesn't amtter at all the tempurature difference (within reason). I usually do a 20 - 30% change in my 70 and the temp stays virtually the same, even thoghut the water running in to it is a few degrees warmer or colder. You shouldn't have any problems if it's between 1-3 º fluctuation.

 

[Zagz]

Your lfs advised to cycle with lots of fish? For future reference, it is much faster and easier on the fish do do a fishless cycle. This article explains it quite well, you can use ammonia instead of shrimp.

Natural daily flucutations in temps don't hurt fish as long as there isn't a huge difference. My 10 gal fluctuates between 78-81 throughout the day to night. It is best to match water temps as much as possible when doing water changes but as noted that will depend greatly on how much water is changed at a time.

 

[JDogg]

lots of fish (per advise of fish store), !

that is because the more fish that die during the cycle they more $$ they get out of you

 

[Rob0504]

Thanks everyone!

Yeah, I will not be going back to that store again. The owner is clueless or just wants sales $. Fortunately I need not buy my fish from him.

On another note, I have only lost only one small neon out of 14 fish in all during my first six weeks. The severums and others are doing well...very tame fish. LOTS OF WATER CHANGES with the Python...what a great way to change water.

Thanks again!

 

[Zagz]

Glad to hear you have a python, it will make those water changes easier. Glad to have you here at AA! The members here will help you through many good and not so good times.

 

[tropicfishman]

I use the rule of one up one down the nI worry. in other words if it goes up one degree or down one degree I don't do anything, anything higher or lower I start to investigate

 

[src]

I would suggest raising your tank temperature to keep the night time temps from dropping more than a degree from daytime temps - 79 or 80. As others have said, it's the constant fluctuations that can be a problem. Most fish will be tolerant of a slightly higher constant temperature, but of course there are always exceptions to the rule.