Fishless Cycle - Where Did Nitrates Go?

[sadguppy]

I have been cycling a 23l fluval edge for just over 2 weeks. I used water from a partly cycled tank showing ammonia, added plants etc from that tank and added fish food most days. There were very high nitrites, the ammonia went down.

Last weekend nitrates were off the scale, so I did w partial water change to bring it down a bit. This week I have only been measuring nitrites, and only a few times... They were above 5. Been away for a few days and come back to 0 ammonia, under 0.25 nitrites and weirdly absolutely no nitrates.

What happened? How can they just disappear completely? I did the test twice with two water samples! No chemicals have been added apart from dechlor.

I have not added fish food for a few days but there are plenty of rotting leaves I have left in to keep it going.

 

[Nosphaer]

That's a bit odd... Nitrate is the favored form of nitrogen by many plants, so they will skew readings, physically, yet I don't know whether they should alter the readings that much.

 

[sadguppy]

I have tested with the API kit, twice, and with a strip just to make sure. No nitrates at all, trace nitrite, no ammonia....
Given that I did no more than a 50% change last weekend, and the readings were well over 80 then, SURELY they should be higher now???

 

[BETTY BOO]

yeah they should be high.not sure whats going on there.personally i would not do anymore water changes.you really have to shake nitrate #2 bottle hard for 3mins to get a proper result.sometimes i give it a little bang on the side.the thing is with using fish food as ammonia source is you dont know how much ammonia is being produced.

 

[sadguppy]

I won't be changing any more water, I guess I will just have to carry on and see what happens.

Is there any chance that the plants have used it up? That is about the only explanation I can think of...Although I admit is it unlikely

 

[Prime Ordeal]

How many and what type of plants do you have?

Did you bang bottle number 2 of the test hard and shake it well as BB suggested?

What type of media do you have in your flter?

 

[sadguppy]

There are about five plants in there including water wisteria which is the only one I can name unfortunately. I like a heavily planted set up. One of the plants isn't doing great and is rotting - I've left it in there as another ammonia source and will take it our before I move any fish in.

I have repeated the test twice, and done a strip test to check. Also my other tank is showing nitrates, so I am convinced it's not an issue with the test. Zero nitrates. I have not measured nitrates since the water change last weekend however I have measured nitrites, which were very high. They have gone down over the past week, from over 5 to less than 0.25.

I have the suggested set up for the edge filter - a sponge, bag of activated carbon and ceramic media. All filter media was bought new when I acquired the tank a few weeks ago and I have not played with it at all since it was set up.

 

[Prime Ordeal]

What is the exact brand of ceramic media as some can reduce nitrate?

 

[sadguppy]

It's the Fluval Edge Biomax like this http/www.petsathome.com/shop/edge-foam-and-biomax-kit-by-fluval-31260

 

[Prime Ordeal]

Yes Biomax is one of the ceramic media that reduces nitrate: http/www.hagen.com/uk/aquatic/product.cfm?CAT=1&SUBCAT=114&PROD_ID=01014560030101

I think this and the combination of your plants solves the problem of the vanishing nitrates.

 

[sadguppy]

Thanks Prime Ordeal, that is good to know. I will keep a close eye on it from now on - fingers crossed that's the end of the cycle then.