Canister Filter Cycling?

[Tolak]

Please tell me if I’m doing the right thing here. I have a 50 gal. tank that I set up an Eheim 2224 filter on 9 days ago. The tank had been running with an under sized hob cascade filter for about 3 months at my house, and for 2 years previous to that at my Dad’s place. I left the hob running figuring that a lot of my biological filtration would be taken care of by it, while the canister had a chance to build up the proper bacteria.

I have been doing 25-30% water changes weekly, along with water tests twice a week since I set up the tank, with ammo-0, nitrites-0, nitrates-10 to 20, temp-75F and ph 7.4.

The tank has 3 pl*cos, 10”, 8”, & 6”, 8 adult platys and 15 platy fry.

I came home this evening and all the fry and most of the adult platys were hovering just below the surface acting as if they were gulping for air. The water looked slightly cloudy also. I immediately did water tests, and my ammo showed just a trace, but nitrites were 1.0, nitrates 40, and ph 6.6.

I just did a 25% water change yesterday, so this worried me. So I did a 30% water change immediately, and filled the water level to about 1” below the top to increase surface agitation. About 2 minutes after the spray bar broke the surface when I was draining the tank, the fry started to swim down from the surface, and scatter about like normal, so I figured more agitation was a good thing. I plan on feeding lightly, probably every other day, testing every day, and changing 25-30% of the water daily until my ammo & nitrites are 0. Am I doing the right thing, wrong thing, anything?

Tolak

 

[Lithril]

Sounds like you're doing the right thing, another option is to put the filter media from your old filter into the bottom of the canister filter. Keep up the water changes though absolutely essential.

 

[smb]

That sounds strange that you would get a pH crash when you were doing a good amount of wc's.

I would say that it might have went thru a mini-cycle but you said that it's been set up for weeks and unless you changed or used chlorinated water on the filters I can't see that.

Obviously something happened. Sounds like they were at the top for oxygen. Surface agitation is good tho so make sure you have some. Did you take the hob out and then this happened or is it still in there? The hob should be good enough for surface agitation altho more is better and I don't know anything about Cascades.

I would do daily wc's but not 25-30%. I would do 5%.

Keep us updated. Hopefully others will be able to help also.

 

[Tolak]

Hi all, back again. I checked on the tank at 7 am before work, and the fish seemed to be doing ok. Since I left the water level a little bit low, the spray bar is about ½” above the surface of the water, spraying across the 12” dimension of the tank and hitting the opposite side creating a rapids type of effect. This morning the largest pl*co (Jaws) was “spray bar surfing” on the side of the tank opposite the spray bar with his nose a good deal of the way in the ‘surf’ and his body swinging to and fro. Looks like fun! This evening the platys were playing in the bubbles, chasing each other around, and otherwise acting normal. I feel relieved

Did water tests again this evening, and the ammo has dropped to just a trace, nitrites to .50, nitrates still at 40, and the ph came up a little to 6.8. The hob filter has been running the entire time, maybe this is just part of the canister cycling and the hob bacteria dying off as the canister is a more powerful filter. Just a newbie guess.

I feel better now that my water seems to be heading towards more normal parameters, and the fish are acting more like themselves. I didn’t feed them last night, and plan on doing 5% or so water changes every evening per smb’s advice. The nitrates being kind of high concerns me, but the ammo & nitrites dropping makes me feel much better.

Thanks to everyone for their help and advice with this situation. Time to grab my bucket & change some water!

Tolak