How Can This Be ?

[Zachary1941]

Hi,
Are now in my Third Week of a fishless cycle.. Everything appears to be going text book style so to speak...This Morning Ammonia was processed from 4 down to Zero and Nitrites are now 5 possibly more.. Ph 7.6...Now here the bit i dont understand .. from the tap the NITRATES read 20....did a NITRATES test this morning on the tank and the NITRATES read 5.. I thought that nitrates could only be lowered by a big water change at the end of the cycle then a smaller weekly one... How can the nitrates be lower in the tank than from the tap water which is the water in the tank ? Regards Zac

 

[LauraFrog]

Are there any live plants in the tank? Also, what filter media is in the filter?

Live plants (or an algal bloom) can absorb a considerable amount of nitrate, they use it like fertiliser (so it's not uncommon, in a tank with a lot of live plants, to see nitrate readings of zero.) Some filter media (the chemical media) can absorb nitrate, but they're very expensive and not commonly used, most people only put them in tanks where the fish are sensitive to nitrate ie german rams and rainbowfish.

There is a bacterially driven process that turns nitrate into nitrogen gas, it's called denitrification and is essential in a reef tank but rare in a freshwater. I think it's safe to rule it out because if it's seen in a freshwater tank, it's in a heavily planted tank with fish and invertebrates, a complete mini eco system that has usually been running for over six months - I'd be very surprised to see denitrification in a tank undergoing a cycle.

I'd say the most likely explanation is that something went wrong with the test. The reagents in the nitrate test are extremely senstive and the test is not particularly accurate (you should treat a nitrate reading as a rough guide, not an absolute value). The chemical in the second bottle tends to settle, which is why you're supposed to kill your arms shaking it before you use it. If you use it frequently, you'll probably get a different reading than if you hardly ever use it, and it's even possible that the temperature of the chemicals might affect the reading. Try re-testing, the nitrate test is a pain in the butt and it just does this sometimes.

 

[Zachary1941]

Thanks Laura,
No Plants only fake ones....Yes did shake the life out the second bottle (lol) and the test tube for a min as per instructions....Thanks, im more concerned with the Ammonia and Nitrites readings.. (Which appear to be going as they should) It was more a interesting observation really.. but none the less strange Thanks again Regards Zac

 

[Zachary1941]

Ahhh,
Right might have found the reason after your post Laura.. dont know if they work But the filter is Jewell Compact.. In it is a green sponge (That is suppose to aborb the Nitrates) Could be a waste of time but might just might be the reason Regards Zac

 

[Zachary1941]

Ahhh,
Right might have found the reason after your post Laura.. dont know if they work But the filter is Jewell Compact.. In it is a green sponge (That is suppose to aborb the Nitrates) Could be a waste of time but might just might be the reason Regards Zac

Hello,
Dont know what to do here..If this green sponge does what it is suppose to do (Aborb Nitrates) Will this prevent the NITRITES from being consumed.? My cycle is going great ....now at the stage that probably the ammonia will be at Zero in 12 hours..within a couple of days..and the nitrites on 5+.Dont wish to disturb any of the filter sponges if i can possibly help it.. but if you guys think this green (So called NITRATE absorbing sponge) should be removed then then i will.. Filter is a Jewell Compact.

Regards Zac

 

[waterdrop]

Zac,

That green so-called nitrate sponge is harmless and won't disturb your cycle. I'd just leave it in and it will gradually become less effective than it already was at removing any nitrates. Nitrate is almost completely a non-issue during cycling except when it gets really high towards the end sometimes and will slow N-Bac development. In those cases a water change will usually lower it and re-kick the final cycling.

~~waterdrop~~

 

[arobinson1984]

Just to second waterdrop.

The green nitrate removal sponge will not affect your cycle, I have a jewul tank and cycled it fine with the green sponge intact

Andy

 

[Zachary1941]

Just to second waterdrop.

The green nitrate removal sponge will not affect your cycle, I have a jewul tank and cycled it fine with the green sponge intact

Andy

Thanks Waterdrop and Andy.. much appreciated ..Regards Zac

 

[waterdrop]

Just to second waterdrop.

The green nitrate removal sponge will not affect your cycle, I have a jewul tank and cycled it fine with the green sponge intact

Andy

Aren't we both just saying the same thing? That the nitrate sponge is no problem, that you can just leave it in? wd

 

[Zachary1941]

Thanks...thats great news.....will leave it in as you both advised.. Regards Zac