Don't Overdo a Water Change

sangria

sangria

Member
I always thought for a water change, the more the merrier. I posted my first thread the other day curious about what was killing (now killed, RIP) my clarkii clowns.
When I changed the water in their tank, I did about 40%, instead of the 10% I normally would. I had overfed them in an incident (I didn't notice all the excess food right away), so I thought I would change more water to keep the parameters in check. I also did some heavy cleaning of the filter and powerhead.
What I did was kill a lot of the beneficial bacteria, and the tank started cycling again. I burned the gills on the clarkiis. I feel awful and irresponsible, but I think it should be addressed because sometimes there can be too much of a good thing. :(
 
spanko

spanko

Active Member
IMO you did not do anything wrong changing the 40%. I believe, without of course being there, that your overfeeding caused the cycle not the water change. The beneficial bacteria live on the hard surfaces in our tanks not in the water column. If you did not remove the excess food, changing the water did little to avoid the cycle.
Again my opinion. Let's see what others say.
 
sepulatian

sepulatian

Moderator
I have changed over 50% of my tank and QT (stocked) without any issues at all. As mentioned, the bacteria is not in the water column, it is on the surfaces. When doing a large water change it is very important to be sure that the PH, SG, and temp all match the tank that is being changed. It is also important to be sure that the new water is thoroughly mixed. If that criteria is met then there is no problem doing a large water change when needed. IMO it was the over feeding that caused the issue. Also, you didn't mention how old this system is and how much live rock you have. I notice that you cleaned your filter at the same time. Biological bacteria does colonize in the filter. If you were relying on that for biological filtration then that would be an issue.
 
reefkprz

reefkprz

Active Member
Originally Posted by sepulatian
http:///forum/post/2627758
I have changed over 50% of my tank and QT (stocked) without any issues at all. As mentioned, the bacteria is not in the water column, it is on the surfaces. When doing a large water change it is very important to be sure that the PH, SG, and temp all match the tank that is being changed. It is also important to be sure that the new water is thoroughly mixed. If that criteria is met then there is no problem doing a large water change when needed. IMO it was the over feeding that caused the issue. Also, you didn't mention how old this system is and how much live rock you have. I notice that you cleaned your filter at the same time. Biological bacteria does colonize in the filter. If you were relying on that for biological filtration then that would be an issue.
I concurr, I myself do 25% once a week and 50% once a month EVERY month.... doing a water change WILL NOT intitiate a spike unless it is performed completely improperly. call it user error, NOT waterchanges are bad.. My advice would be: If your going to do a large water change make sure it is done properly, to avoid complications.
 
sangria

sangria

Member
The tank is 20 gallons and has about 15 lbs of live rock in it. It is 4 months old, so still relatively new.
In good news, the larger of the clarkiis (maybe 1.25 inches) seems to be pulling through. Her gills are clearly burned, however.
I guess the thread should be "Don't Overfeed your Fish" instead.
 
bill109

bill109

Active Member
is bacteria on hob filter pads? if you change those will it it harm anything?
dont mean to jack the thread lol
 
reefkprz

reefkprz

Active Member
some bacteria will eventually grow on your filter pads but I wouldnt really be concerned about the amount if you change your pads on a regular basis (aka once a month or more often) the amount will be quite insignifigant in the grand scheme of things.
 
florida joe

florida joe

Well-Known Member
Originally Posted by reefkprZ
http:///forum/post/2630802
some bacteria will eventually grow on your filter pads but I wouldnt really be concerned about the amount if you change your pads on a regular basis (aka once a month or more often) the amount will be quite insignifigant in the grand scheme of things.
Reef my good friend I have to disagree with you on this one point I think you get a great deal of bio-filtration on your filter pads your total water volume will at sometime pass through the pads feeding an ever growing colony of bacteria the food is in a way being brought to them. That being said I fully aggress that after looking at the posters tank size that changing out his filter box media will not cause an over load on his system but in smaller tanks some which people feel going with large size filters are better the removing of the filter pads my cause a larger then expected decreases in nitrifying bacteria. I would recommend for those with smaller tanks to simply cut the old filter material in half and place a new one in with the half of the old one to get a jump start on replenishing nitrification.
 
sepulatian

sepulatian

Moderator
Originally Posted by florida joe
http:///forum/post/2630830
Reef my good friend I have to disagree with you on this one point I think you get a great deal of bio-filtration on your filter pads your total water volume will at sometime pass through the pads feeding an ever growing colony of bacteria the food is in a way being brought to them. That being said I fully aggress that after looking at the posters tank size that changing out his filter box media will not cause an over load on his system but in smaller tanks some which people feel going with large size filters are better the removing of the filter pads my cause a larger then expected decreases in nitrifying bacteria. I would recommend for those with smaller tanks to simply cut the old filter material in half and place a new one in with the half of the old one to get a jump start on replenishing nitrification.
This tank is only a 20 gallon. I am not sure what you would consider small. I can see how in a new tank the system may rely on the biological filtration in the filter pads. Once the tank is mature the amount of bacteria on the filter pads will not matter much. Cutting the pad in half would help for now. Some people like to run two filters so that they can change one at a time. There will always be biological bacteria on one of the pads.
 
florida joe

florida joe

Well-Known Member
Originally Posted by bill109
http:///forum/post/2630746
is bacteria on hob filter pads? if you change those will it it harm anything?
dont mean to jack the thread lol
Um Sir Q I was responding to Bill 109s post and unless you know something I don’t I can only go by his profile and that states he has a 90 g tank
Now lets assume I have a 20-gallon tank and my tank is in equilibrium. I take out my filter pads and also introduce a new fish. I can feel safe that my bio-filtration with out the benefit of the nitrifying bacteria on the pads can compensate for the loss
 
sepulatian

sepulatian

Moderator
Originally Posted by florida joe
http:///forum/post/2630845
Um Sir Q I was responding to Bill 109s post and unless you know something I don’t I can only go by his profile and that states he has a 90 g tank
Now lets assume I have a 20-gallon tank and my tank is in equilibrium. I take out my filter pads and also introduce a new fish. I can feel safe that my bio-filtration with out the benefit of the nitrifying bacteria on the pads cans compensate for the loss
LOL sorry, I thought you were talking about the OP with the 20. Maybe I am missing what you are saying on that last part. Please correct me if I am. Are you saying that in a 20 gallon it would be safer than in a 90 to remove the filter pads and rely on the LR and LS?
 
florida joe

florida joe

Well-Known Member
Originally Posted by sepulatian
http:///forum/post/2630857
LOL sorry, I thought you were talking about the OP with the 20. Maybe I am missing what you are saying on that last part. Please correct me if I am. Are you saying that in a 20 gallon it would be safer than in a 90 to remove the filter pads and rely on the LR and LS?
just the reverse
 
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