Fishless Cycling Tank - What To Do Now?

Here’s the details:
10 gallon planted tank fishless cycling. I went on vacation for five days so I tossed in a piece of raw shrimp, set the heater to about 82 and left. My boyfriend, without telling me, turned off the lights and air wall. So, only water movement was from my filter.

Came back today to a slightly greenish tank. Pretty sure it was from some of the dead water wisteria floating around in the tank, it’s not cloudy.

My readings are this:
0 ammonia
5 nitrites
160 nitrates

I haven’t done any water changes yet. I turned the heater down to 78, turned on the air wall, and turned on the lights. What should I do now?

 

Water change

 

Here’s the details:
10 gallon planted tank fishless cycling. I went on vacation for five days so I tossed in a piece of raw shrimp, set the heater to about 82 and left. My boyfriend, without telling me, turned off the lights and air wall. So, only water movement was from my filter.

Came back today to a slightly greenish tank. Pretty sure it was from some of the dead water wisteria floating around in the tank, it’s not cloudy.

My readings are this:
0 ammonia
5 nitrites
160 nitrates

I haven’t done any water changes yet. I turned the heater down to 78, turned on the air wall, and turned on the lights. What should I do now?

Well it sounds like nitrites are being converted to nitrates (big time lol) but you want that to get down to 0 and in the meantime you need to continue providing a source of ammonia so that bacteria doesn't die off while you wait for the other types to handle the nitrites.

 

Do a large water change, your cycle is stalled bc of the nitrates.

 

Water change

How big of a water change?

Well it sounds like nitrites are being converted to nitrates (big time lol) but you want that to get down to 0 and in the meantime you need to continue providing a source of ammonia so that bacteria doesn't die off while you wait for the other types to handle the nitrites.

I’ll replace the shrimp with half of one.

 

Do a large water change, your cycle is stalled bc of the nitrates.

I actually agree with this. 50% should do it. I got semI stalled at nitrite stage but also had high nitrates. Had to inadvertently do a WC and it jump started the cycle.

 

If your nitrates are 160ppm, Id do 50% now, 50% tomorrow and 50% the next day to get them to 20ppm.

 

If your nitrates are 160ppm, Id do 50% now, 50% tomorrow and 50% the next day to get them to 20ppm.

But there are no fish in there, would it be better to wait to see the nitrite results rather than removing them to the point where subsequent water tests would be inadmissible because nitrites have been so diminished not from BB progress but from water changes alone?
Then when nitrites are zero do the necessary water changes as you suggest to bring them to a safe level for adding fish?

 

So then should I do a single 50% water change and see what happens?

 

So then should I do a single 50% water change and see what happens?

I'd do 50%, retest to confirm your new parameters, add the half shrimp, and go from there.

 

You can do whatever you want. Your nitrates are only going to go up from here, that's why we do water changes in the first place. To bring them down. At some point, you'll need to bring them down. Whether you do it back to back to back or wait until they build up more, its your call. Might as well get them down now before they get really out of control.

 

You can do whatever you want. Your nitrates are only going to go up from here, that's why we do water changes in the first place. To bring them down. At some point, you'll need to bring them down. Whether you do it back to back to back or wait until they build up more, its your call. Might as well get them down now before they get really out of control.

Yeah, that's a good point. Branching out from that a bit I would (personally) say if after a 50% change you don't notice a substantive drop in nitrates (assuming you tested at the max of the scale) I would do another 50% change.

 

Update!

Nitrites and Nitrates still aren’t going down. Did 3 back to back 75% water changes and my readings went from:
.5 ammonia
5 nitrites
160 nitrates

To:
.5 ammonia
5 nitrites
20 nitrates

BUT I woke up today and my nitrates are right back at 160 again. What is going on??