Fishless Cycle Question, Please Help

[Boilerwxman]

I have a 15 gallon column tank. I have been cycling it for about 2 weeks. It really took off this last week. My latest results:

pH is about 8.2 (Tap water base is around 8)
Ammonia is going from 4ppm to 0 ppm in less than 24 hours
Nitrite is off the Chart on my test kit
Nitrate is around 5 ppm

I gave my tank a boost by putting 2 plastic plants and gravel from an established 5 gallon tank where I am currently housing 3 young Mollies.

The Ammonia & Nitrite on this tank is at 0 and Nitrate is around 40 ppm

I know I am close with the 15 gallon, I just have a couple of questions:
1) With the ammonia going to 0 so quickly and the nitrites so high. Should I a) go every other day on Ammonia or put less in? b) I have tried a few water changes this week and after a 50% and 40% had no luck in getting the nitrites to a readable level. Obviously they are spiking

2) Should I try to add more gravel from the established tank to help with the nitrite eating bacteria? I already have a nylon bag of gravel in there I added this week.

Any other advice would be appreciate it. I understand being patient but being this close wonder if there is something I need to do to keep this from stalling

Thank you

 

[Scouser]

Just wait for the nitrite > nitrate BB to develop a bit more.

With 5ppm they are processing but the colony size isn't large enough to process what trites are there.

As for ammo I'd dose a smaller amount, maybe 2ppm just for now while the BB colonies grow.

This is all in my opinion though, some may have way different advice.

 

[HeatherW]

as long as your PH is holding you can keep dosing up to 4ppm but keep a close eye on your PH. if it starts to drop then I would drop your ammonia dosing down to 2ppm until you can get your nitrites readable. then once everything starts to settle down you can slowly start to increase your ammonia dosing back up to the 4ppm again

 

[librarygirl]

For two weeks in your readings look good. The nitrite phase can take 3 weeks on average so it's normal for them to spike. You can do water changes if you want, up to you, won't hurt anything but probably not needed yet. How long has the nitrite been 5+? Keep an eye on PH too, if it drops it can stall things.

Although are you setting this tank up to upgrade your mollies? If so there's no need to cycle it separately. Just move the filter over (and any other decor you want) to the 15 gal from the 5 and it'll be instantly cycled. Of course a 5 gal filter can't filter a 15 gal so you could either 1) run the 5 gals filter on the 15 gal along with the new filter for a month or so until the the new filter has enough bacteria or 2) move all of the filter media from the 5 gal to the new filter and then if there's any room left just fill it with new media.

3 mollies in a 5 gal is way overstocked. Nitrates on that tank are 40? Time for some water changes; you want to keep them <20 (<10 optimum) but with that high of a bioload in a 5 gal it's going to be tough keeping nitrate to a decent level.