Bactierial Bloom?

[Susannah]

Hi! I've lurked here for quite some time but never actually registered or posted. I have a quick question...

I came to work this morning and my normally crystal clear aquarium was in the throes of a very obvious bacterial bloom. I asked my husband (we work together) if he had noticed anything yesterday afternoon before he left and he said no but then he told me that he was pretty sure I hadn't changed the filter in quite some time and so he changed it last night. Ah... the "helpful" spouse.

I tried to explain that I didn't change the filter on purpose because my 39 gallon tank was doing marvelously, all the water levels tested perfect week in and week out so other than small regular water changes and periodic gravel vacuuming, I kind of let it do its thing.

My question is this... would that filter replacement have been enough to trigger the bacterial bloom or is there possibly a larger issue here? I'm inclined to think the filter media change caused it because that's the only thing that has changed in months. I know I haven't given enough information about my set-up here but I wasn't sure what details were pertinent and which ones weren't and I didn't want to overwhelm with unnecessary information.

Any thoughts would be appreciated! Thanks so much!

Susannah

 

[OldMan47]

The filter media change may have reset your cycle to day 1.

I have no idea why it would affect water clarity though.

 

[Myuu]

The removal of the mature filter media is definitely the cause of your bacteria bloom. Unfortunately, your tank is going to have to cycle again, although it'll probably go a little faster due to the smaller amounts of bacteria that were present in the tank. Did your spouse through all of the media out? You should probably test your water because the ammonia and nitrites with probably be on the rise.

 

[minnnt]

The filter media change may have reset your cycle to day 1.

I have no idea why it would affect water clarity though.

Because of a bacterial bloom surely? If the mature media has been removed for new then there is no bacteria to deal with ammonia which would probably cause the bloom affecting clarity?

 

[Susannah]

The removal of the mature filter media is definitely the cause of your bacteria bloom. Unfortunately, your tank is going to have to cycle again, although it'll probably go a little faster due to the smaller amounts of bacteria that were present in the tank. Did your spouse through all of the media out? You should probably test your water because the ammonia and nitrites with probably be on the rise.

I'm afraid he did. I've tested it several times today and so far, ammonia and nitrites are still at 0 although my nitrates are hovering around 20 ppm and the pH is slightly low at 6.5 (but it has always hovered around this point). Also (I just retested) now the general hardness looks to be about 120ppm and I've never noticed that being an issue before. Although to be perfectly honest... that's not a level that I really know much about what it might mean.

 

[Prime Ordeal]

Susannah how are you testing your water? Are you using test strips? If so they aren't accurate enough for the job and if you've now got a brand new filter sponge then you will begin to see ammonia rising eventually, but with test strips it'll probably be too late and your fish will be suffering.