High Nitrates at the End of the Cycle

[RayAllen3422]

My cycle appears to have ended last night and ammonia and nitrites are going to 0 within 24 hours of dosing additional ammonia. The problem I have is that I tested nitrates and they are the highest possible on the Salifert test kit (100). I have searched and read a lot of information but I always thought nitrates would not come down on there own and had to be removed via a water change at the end of the cycle. However, recently I have read posts about people waiting for nitrates to come to zero before moving on. Will nitrates come down on their own?

The tank is empty (no life) and I used dry rock to cycle. The lights are just coming on today to start any algae bloom at which point I will add a CUC. I am also getting chaeto and starting my refug this weekend. My plan right now is to do a 50% water change this evening. Any other recommendations on how to deal with these high nitrates? Thanks for any input.

 

[pyithar]

the nitrates will come down via denitrification and when they're used by growing algae. but the process might take some time. so your 50% water change plan is better. regular water changes, a good skimmer, enough liverocks, not overstocking/overfeeding will help lower the nitrate.

 

[RayAllen3422]

the nitrates will come down via denitrification and when they're used by growing algae. but the process might take some time. so your 50% water change plan is better. regular water changes, a good skimmer, enough liverocks, not overstocking/overfeeding will help lower the nitrate.

The plan is to do 10% weekly water changes (automatically through the Neptune DOS). I have a decent skinner but it isn't pulling much out right now because nothing is making waste. I have probably 160-170 lbs of live rock between the sump and DT in a 125 gallon tank. I am not feeding anything right now except a small pinch of fish food a couple times a week to keep the bacteria alive until I get life in the tank. The plan is to start with a pair of clowns after the CUC arrives. But the clowns will be in TTM and QT for about 6 weeks. I think I am doing everything I should but I want to have all my bases covered. What is an acceptable level of nitrates to add the CUC?

 

[thegrun]

I would actually do a 100% water change as soon as you can. If you leave your nitrates high it will be absorbed into your rocks and they in turn will start to feed algae growth. I suspect you either had a very high initial ammonia level during the cycle or you added ammonia multiple times during the cycle which isn't necessary and only serves to increase your nitrates at the end of the cycle.
In most tanks the nitrates will not come down on their own or only do so very slowly. 10% water changes will probably never lower your nitrate levels, make a 100% water change and start off on the right foot.

 

[RayAllen3422]

I would actually do a 100% water change as soon as you can. If you leave your nitrates high it will be absorbed into your rocks and they in turn will start to feed algae growth. I suspect you either had a very high initial ammonia level during the cycle or you added ammonia multiple times during the cycle which isn't necessary and only serves to increase your nitrates at the end of the cycle.
In most tanks the nitrates will not come down on their own or only do so very slowly. 10% water changes will probably never lower your nitrate levels, make a 100% water change and start off on the right foot.

I dosed ammonia to 2 PPM using pure ammonia to start and added a pinch of fish food maybe 3 times to see if ammonia and nitrates would be processed in 24 hours.

100% water change is easily doable and I will take care of this weekend as soon as I make up more water. I had about 50% made up to be ready for the end of the cycle but I am going to need some other containers to do a 100% change. This makes a lot of sense to me and was kind of where my mind was going.

 

[CStrickland]

Nitrate does not absorb into rocks for later release. It simply cannot bind to calcium carbonate the way phosphate does. You don't need to worry about that, but a big water change is an easy way to knock them down since the tanks not stocked, no real downside.

 

[LQT]

By the way, love your handle... Sweet Ray lived upstairs from me in the dorm my freshman year at UConn. Was super nice and cool. My favorite Husky ever!

 

[RayAllen3422]

Nitrate does not absorb into rocks for later release. It simply cannot bind to calcium carbonate the way phosphate does. You don't need to worry about that, but a big water change is an easy way to knock them down since the tanks not stocked, no real downside.

Your quote in your signature is great BTW. Thanks for the insight. I will do the big water change this weekend and hopefully everything will be better then.

 

[RayAllen3422]

By the way, love your handle... Sweet Ray lived upstairs from me in the dorm my freshman year at UConn. Was super nice and cool. My favorite Husky ever!

Thanks.

 

[CStrickland]

Your quote in your signature is great BTW.

I just thought of something else, make sure your nitrites are all the way gone before you test nitrates. I can't tell from your post how long trites have been zero for, but they can confuse a nitrate test and make it read super high false positive.

 

[RayAllen3422]

I just thought of something else, make sure your nitrites are all the way gone before you test nitrates. I can't tell from your post how long trites have been zero for, but they can confuse a nitrate test and make it read super high false positive.

Nitrites have only been gone 2 days.

 

[CStrickland]

Nah it's prolly not that then. The bac that clears nitrates comes a little slower, I'm sure it'll catch up.

 

[RayAllen3422]

Nah it's prolly not that then. The bac that clears nitrates comes a little slower, I'm sure it'll catch up.

I just retested and now I am showing a little ammonia and nitrites again. Not sure what is going. It is barely a color but yesterday they were both clear. I'm going to test again tomorrow and see what's up. Still planning for a 100% water change once I get consecutive days with ammonia and nitrites at zero. It's been 9 weeks so I thought I was golden.

 

[RayAllen3422]

I did as close to a 100% water change a I could (a little water was left with the sand) and nitrates are now under 10 PPM. I should be good to go now.