A cycling question

[WendiDell]

I have a 55g Cichlid tank that's cycled, and an empty tank that I'm cycling to be an Angelfish tank.
I'm getting ready to do a PWC in the Cichlid tank because the Nitrates are a little higher than I like. It's pH 8.2, temp. 78, Ammonia 0, Nitrites 0, Nitrates hit 40 just today.
I have 2 Magnum H.O.T. canister filters on the Cichlid tank. On the empty tank I have 1 Magnum H.O.T. filter and a Emperor 400 filter. If I were to change out 1 of the established Cichlid canister filters for the unestablished canister filter, would it through my established tank into another cycle or would it be OK?
I want to cycle the other tank, but not at the cost of my Cichlid tank.

 

[HUKIT]

Depending on the bioload of the cichlid tank it should be ok. If the load is high you may see a mini cycle but check the water parameters after a few days to sure. Otherwise it's instant cycle time for the angel tank.

 

[WendiDell]

Depending on the bioload of the cichlid tank it should be OK. If the load is high you may see a mini cycle but check the water parameters after a few days to sure. Otherwise it's instant cycle time for the angel tank.

A strange thing happened today. Last night I did a 25% PWC to lower the Nitrates a bit. They were at 40 and I prefer them to be around 10-20. I tested after the PWC and the Nitrates had dropped to 5. So I decided to not switch the filters.
I tested the the water again this morning and the nitrates had jumped to 80, after the PWC.
So I switched one of the canister filters from the tank with high Nitrates with one of the filters from the tank with 0 nitrates.
My cichlid tank was,
pH 8.2 Ammonia 0, Nitrites 0, Nitrates 80.
The tank that I'm doing a fish less cycle with is,
pH 7.0, Ammonia 4.0, Nitrites 0, Nitrates 0.
It will be interesting to find out what the water is in both tanks tomorrow.

 

[HUKIT]

Are you using the API kit? If so are you shaking the snot out of those bottles prior to testing?

 

[mfdrookie516]

Yeah, you're not getting accurate results. Assuming your water is nitrate free, the absolute most you can drop your nitrates is 25% with a 25% pwc.

 

[WendiDell]

Yeah, you're not getting accurate results. Assuming your water is nitrate free, the absolute most you can drop your nitrates is 25% with a 25% pwc.

I always use API FW Master Kit and the kit is only 2 weeks old.

I think the problem is that you didn't notice that those test results are on 2 separate tanks. The first set of readings, pH 8.2, Ammonia 0, Nitrite 0, Nitrate 80, are on my established Cichlid tank.
The second set of readings, pH 7.0, Ammonia 4.0 Nitrite 0, Nitrate 0, is on another tank that I am trying to do a fishless cycle.

Because the Nitrates were up to 80, which is higher than I like, on my already cycled tank, I switched 1 of the 2 HOB canister filters from my cycled tank, to the uncycled tank to assist in the fishless cycling.
I also put the HOB canister filter from the uncycled tank onto the cycled tank. Which caused a temporary drop in the Nitrates.
And yes I shake the s:censor:t out of it every time I test. I read the directions that came with the test kit.

The actual part that I was wondering about was why would the Nitrates go from 40 (before PWC)up to 80 the day after a PWC?

Now that I've removed 1 HOB canister filter from the cycled tank and replaced it with another non cycled HOB canister the new Nitrate readings are between 10-20. I can't tell the difference in the oranges on the color chart. Given more time than 8 hours I'm sure the Nitrates will go up on both tanks. Everything else has stayed the same, pH 8.2, Ammonia 0, Nitrites 0.

The uncycled tank hasn't changed yet. I'm sure it will start to change soon, now that I've seeded it with filter media from my cycled tank.
Dose this clear anything up? I hope.
One last thing, when I tested the Nitrates last night. It was to soon after the PWC to be accurate.
I know better than to test that soon, but the tank is in my 10 year old grandsons room and he needed to go to sleep. Normally I wait a few hours for the water to balance it's self.