Tank won't finish cycling

[brilovescats]

Hello -
I have a 75 gal that I set up very successfully, and I have been trying to set up a pico tank to live at my desk in my office. Problem is - it's been set up for about 8 months now, and it will never finish cycling, nitrates stay consistently between 16-24. Any thoughts/ideas that would help it finish? Here's my tank and what I've done:
- 5 gal fluval ECO
- About 5lbs of dry Fiji rock
- Live sand
- Activated charcoal
- AF life bio fil changed every 6ish weeks
- Pico powerhead and heater
- AF probiotic reef salt

I've tried:
- Dr Tim's refresh
- Dr Tim's waste away
- Red Sea NO3PO4-X
- AF bio S
- AF pro bio F
- AF pro bio S
- AF-NP pro
- ZeoMix
- Various water change intervals (2x week vs. 1x vs. every 2 weeks)

 

[rich nyc]

What about just bring water from your 75 gallon and call it a day. I will probably get crucified for saying this.

 

[WWIII]

Technically a tank never finishes cycling, but I understand what you mean in that you would like nitrates to be lower consistently. I'm wondering if all the aquaforest stuff is adding nitrates to the system? Have you tried a water change of 50%?

 

[brilovescats]

Technically a tank never finishes cycling, but I understand what you mean in that you would like nitrates to be lower consistently. I'm wondering if all the aquaforest stuff is adding nitrates to the system? Have you tried a water change of 50%?

Thanks for the quick reply! I've done various water change sizes at various intervals to see if it helps. I've also tried not adding anything for a couple weeks and the nitrates still didn't go down, to see if I was messing around too much, with no change. [emoji848]

 

[brilovescats]

What about just bring water from your 75 gallon and call it a day. I will probably get crucified for saying this.

Yeah, I tried adding a cup from the other tank, but I have an algae problem in my other tank, so I’m trying to avoid doing water changes from one tank to another for now.

 

[redfishbluefish]

A cycle is "done" when bacteria can process ammonia to nitrite to nitrate. Once you get to nitrate, that's it. Denitrification, that is, converting nitrate to nitrogen, only happens in low/no oxygen environments....so it really doesn't happen appreciably in our tanks. Therefore nitrate needs to be exported....taken out of our tanks. This can be done in a number of ways....skimmer, water changes, refugium, carbon dosing, etc. After eight months I've got to believe your cycle is done.

 

[mjlash22]

What else is in the tank? Any livestock? Are you feeding? If so regular/irregular schedule?

 

[brilovescats]

What else is in the tank? Any livestock? Are you feeding? If so regular/irregular schedule?

No, nothing in the tank, just rocks and water. I didn’t want to put anything in with nitrates that high.

 

[brilovescats]

A cycle is "done" when bacteria can process ammonia to nitrite to nitrate. Once you get to nitrate, that's it. Denitrification, that is, converting nitrate to nitrogen, only happens in low/no oxygen environments....so it really doesn't happen appreciably in our tanks. Therefore nitrate needs to be exported....taken out of our tanks. This can be done in a number of ways....skimmer, water changes, refugium, carbon dosing, etc. After eight months I've got to believe your cycle is done.

Certainly something to consider... where it’s so small, water changes has been my method of removal. What are your thoughts on some sort of tiny skimmer? Does one even exist?

 

[smiley28]

What inhabitants are in the tank? What all do you put in the tank?

So I was hesitating when originally posting and I guess I took awhile cause a few post were made. So seeing what has been discussed maybe you should only do water changes and nothing else for a few months.

 

[ChrisOFL]

If it's 5 gallons do a 100% water change and you'll be back at 0 or close enough to it. You will probably never see that tank begin dentrifying because it is just too small.

 

[siggy]

You will probably never see that tank begin dentrifying because it is just too small.

Who does the reef in a vase? He may be able to shed more light on this. I think he did Daily water changes?

 

[brilovescats]

What inhabitants are in the tank? What all do you put in the tank?

So I was hesitating when originally posting and I guess I took awhile cause a few post were made. So seeing what has been discussed maybe you should only do water changes and nothing else for a few months.

As above, nothing in my tank at all. What I put in my tank is above, but right now, I just put water in.

 

[brilovescats]

If it's 5 gallons do a 100% water change and you'll be back at 0 or close enough to it. You will probably never see that tank begin dentrifying because it is just too small.

Hmmm... so with the nitrate at 16, if I do a near 100% change once a week or so, like maybe 80%, should work? Good to know that it will likely never begin denitrifying. Makes me feel better, I thought I was doing something wrong.

 

[ChrisOFL]

Who does the reef in a vase? He may be able to shed more light on this

You're probably talking about brandon429. He's got a great vase but he does 100% water changes all the time after heavy feeding and demonstrates how you can clean a sand bed without a cycle.

 

[ChrisOFL]

Hmmm... so with the nitrate at 16, if I do a near 100% change once a week or so, like maybe 80%, should work? Good to know that it will likely never begin denitrifying. Makes me feel better, I thought I was doing something wrong.

Do 100% whenever you want on a tank that size. You have the nitrifying bacteria that lives in the rocks and sand which is all you need. I feel bad you've been waiting 8 months with no livestock.

 

[SashimiTurtle]

What are your ammonia and nitrite levels? With nitrates at 16-24 and 8 months old... I'd say you've been "cycled" for quite some time.

 

[brilovescats]

Do 100% whenever you want on a tank that size. You have the nitrifying bacteria that lives in the rocks and sand which is all you need. I feel bad you've been waiting 8 months with no livestock.

Haha I guess I should have asked sooner! I had expected it would start denitrifying.

 

[ChrisOFL]

Haha I guess I should have asked sooner! I had expected it would start denitrifying.

Denitification could occur but you would have to provide some special conditions that aren't worth trying in a small tank because a water change costs like $3.

 

[brilovescats]

What are your ammonia and nitrite levels? With nitrates at 16-24 and 8 months old... I'd say you've been "cycled" for quite some time.

Ammonia is a hair above zero, 0.12 max, nitrite is zero as of right now.