end of cycle issue?

[tombin]

I thought I was close to the end of my cycle. I was going from 4ppm to 0 ammo and 0 nitrite in 24 hours. Before I went out an bought fish I did a 90% water change. and dosed back up to 4ppm. Now my ammo isn't dropping at all in 24 hours.

When I did my water change i unplugged my HOB filter, used my python to fill the tank, let the water get back up to 80 degrees (about 3 hours), dosed the tank with prime conditioner, and plugged my filter back in.

Did I miss something that killed all my bacteria?

 

[eco23]

Did you add Prime before or after adding the raw tap water? I assume you're on a municipal water source (containing chlorine)?

 

[-Mac-]

I am confused by the timing in your post:

Did you allow the tank to sit, empty of water for three hours
Or
Did you fill up the aquarium, allow the tank to sit for three hours without the filter running, then condition the water and turn the filter back on.
Or
Did you fill up the tank, condition the water immediately then allow it to sit for three hours without the filter running?

 

[tombin]

Thank you for the replies. To answer both questions:

Eco - I added prime after adding raw tap water.

-Mac- - I filled the tank, added prime immediately after, then allow it to sit for 3 hours without the filter running.

 

[eco23]

Thank you for the replies. To answer both questions:

Eco - I added prime after adding raw tap water.

-Mac- - I filled the tank, added prime immediately after, then allow it to sit for 3 hours without the filter running.

Hmm...well first, make sure you do it the other way around. Drain the water, add Prime based off the total volume of the tank (not just what you're replacing), then after that refill with temp matched water. I use a Python as well and I do it usually 2x per week in that way.

If the filter wasn't running before the Prime, that will be your saving grace. Chlorine is added to water specifically to kill bacteria..so chances are that much of the BB on the decorations, walls, substrate, etc...got nuked depending on how long it took before the a prime was able to detoxify the chlorine.

This is tricky because everything about this is part good and part bad. The fact the filter was off is a good thing since raw tap water was not pulled through your filter media. The majority of the nitrifying bacteria live there, and if chlorinated tap water was run through...it could have been devastating. However, by not having the filter running for those 3 hours, the Prime was also not being circulated with the new water...so most likely would have not neutralized the chlorine sitting in the tank, thereby damaging all of the bacteria in the actual tank.

It's surprising and another mystery why conversion would have halted entirely. Since the majority of the BB is in the filter media, there should still be large amounts of bacteria causing conversion.

This shouldn't be related since you just did a massive water change...but pH crashes can be a common cause of things pressing the pause or rewind button. Check what it is now (which should be reasonable), but there's also the possibility that the end of your cycle totally crashed the pH and maybe you didn't see it before the pwc. A serious pH crash will shock the ammo > no2 bacteria for several days, and it's perfectly plausible that it's basically gone dormant for a time while it recovers.

If you've got any other strange occurrences you can think to mention I'd love to hear them, but in the mean time I think we just need to wait and see what happens for the next few days. One thing I will say...unless some calamity (like running chlorine through the filter) occurred, this is probably not a disaster...most likely something that will set you back a small ways.

I'll be very interested to hear what happens...so keep us posted

 

[-Mac-]

It is possible that not being completely covered in water may have caused some, though certainly not a complete, die off of the in your HOB

Why you are allowing the water to 'warm back up' before running the filter again?

 

[tombin]

Thanks for the advice.

Eco - to verify what your saying - after taking water out of the tank, dose with enough prime for the full water change, then fill the tank? This should kill the chlorine in my tap water as its added?

Also - I'm using a Marineland Penguin 150 HOB filter. These have a biowheel which water is just being poured over the biowheel. Would it be better to have a second HOB filter where the water is being forced through the bio-filter? If so - what is recommended?

 

[eco23]

Yeah, turn off the filter, drain the water you're removing, add Prime directly to the tank based off the total volume (so if it's a 55 gallon tank you'd use a full capful), refill with temperature matched water, turn the filter back on and you're done.

Unfortunately by not adding Prime before hand, it basically put a mild bleach solution (the chlorine) into the tank and let it sit in there for a while. Chlorine kills bacteria...so bad combination. If you'd had your filter running before adding the Prime it would have been a very bad situation indeed since that's where most of the bacteria is.

I'm not really familiar with bio-wheel filters other than the cheap one I use on my QT. The majority of people here recommend the AquaClear HOB filters, and if the tank is large enough canisters are the way to go IMO. It's really about gallons per hour (GPH) and what the filter is rated for. The best rule of thumb is to have double the filtration rated on the tank. So...on my 46 gallon I have a Fluval 405 which is rated for 100 gallons...it's the perfect size and does an awesome job at filtering and providing tons of space for the beneficial bacteria to colonize.

If you end up switching filters, obviously make sure you keep every piece of filter media from the old...and jam it into the new so you don't lose all the bacteria which has colonized in there.