[insensate]

Hi all... I am new to this hobby and having problem cycling my tank... I have been through a lot of forums and information on the net about cycling now and haven't been able to figure it out... here is a little background on the tank:

I bought a used 40g breeder two months ago... filled it up with water and let it sit for a week to make sure there were no leaks... then i added filter/heater and let them run for two days to make sure they were working properly... then i planted it moderately... let the whole setup sit for about a week till i started seeing some plant growth... at this point i added two Siamese Algae Eaters, started testing my water with API freshwater master kit daily... i didn't see reading for any ammonia or nitrites for a week... I asked a LFS and they told me the tank was too big for two little SAE and i should add more fish to it... I ended up adding 8 platies to the tank... after that i started seeing ammonia... i kept up with water changes to make sure ammonia was close to 0.25ppm... i saw ammonia get close to 1ppm and then went down to 0.25ppm... but never went all the way down to 0... i never saw nitrites show up... i wasn't checking for nitrates cuz i thought i should see nitrites first... now for the past three weeks ammonia has been sitting at 0.25ppm and not moving at all... still no nitrites... but there are nitrates around 20ppm.... i do 25% water changes weekly just to keep water clean... i tested my tap water for it shows 0.25ppm ammonia, 0 nitrites, ~0 nitrates... i am pretty sure my tap water didn't have any ammonia when i tested it two months ago... so i figured that maybe my testing kit was bad and giving me false positive on ammonia... so i took my tank water to PetSmart, they did the strip test and it showed no ammonia... but i know strips are not accurate... so i took it to the LFS and they tested with tetra test kit and it showed 0.25ppm as well

all my fish seem really healthy and active... don't show any sign of stress... which i take as a good sign... so i am pretty confused what is going on with the cycle... will appreciate any ideas / help

Tank: 40g (36"L, 15"W, 17"H)
Filter: AquaClear 50, Eheim 2217
Fish: 8 Platies, 2 SAE (~15 frys)
Plant: Amazon Sword, Java Moss, Anubias Nana, Wisteria
Temp: 78F
PH: 7.8
Ammonia: 0.25ppm
Nitrite: 0ppm
Nitrates: ~20ppm

 

[lorax84]

Generally once you see nitrates you are one the right path because nitrates are a result of bacteria metabolizing nitrites. Personally I would not be worried, especially with your tap water ammonia being 0.25ppm strait out of the tap. That being said, I wouldn't go throw a bunch more fish in the tank right away, wait a couple of weeks and if the numbers are the same you should be good to go.

 

[Byron]

I also agree, you have no problem. But I will explain a bit.

First, plants need nitrogen as one of their macro-nutrients, and aquatic plants prefer it as ammonium. The ammonia produced by the fish and organic processes in the tank will be grabbed by the plants and they usually out-compete nitrosomonas bacteria for it; plants convert it to ammonium and assimilate it. In planted tanks it is rare to see any cycling (unless the fish are way overstocked for the plants, which is not the case here). Thus, you will not detect ammonia or nitrite normally. Nitrates will usually be low, sometimes zero, in planted tanks, depending upon the number of plants and number of fish. So that explains your not seeing a cycle. All's well on that front.

As for the ammonia in the tap water, I would recommend you use a water conditioner that detoxifies ammonia. Several do, and they work by changing ammonia to ammonium. Plants use ammonium as I mentioned, and nitrosomonas bacteria also use ammonia or ammonium equally. The conditioner will handle the sudden influx of ammonia at the water change. Conditioners tend to give out in about 24 hours, but by then the plants and bacteria will be able to handle any excess ammonium.

Last point, the API test kit for nitrate instructs you to shake regent #2 for 30 seconds; in fact, it should be shaken for 2 minutes before adding the drops to the tube of water. Otherwise the results may be inaccurate, usually higher than the actual nitrate.

Byron.

 

[insensate]

I also agree, you have no problem. But I will explain a bit.

First, plants need nitrogen as one of their macro-nutrients, and aquatic plants prefer it as ammonium. The ammonia produced by the fish and organic processes in the tank will be grabbed by the plants and they usually out-compete nitrosomonas bacteria for it; plants convert it to ammonium and assimilate it. In planted tanks it is rare to see any cycling (unless the fish are way overstocked for the plants, which is not the case here). Thus, you will not detect ammonia or nitrite normally.

thanks byron... i was worried about ammonia/ammonium showing up in the tank even after 24hours... but i think i have something wrong with my test kit... i tested bottled water (Arrowhead and Crystal Geyser) and they both show same color of ammonia as my tank water (very light shade of green)... i have ordered a new ammonia kit just in case to see if that helps

As for the ammonia in the tap water, I would recommend you use a water conditioner that detoxifies ammonia. Several do, and they work by changing ammonia to ammonium. Plants use ammonium as I mentioned, and nitrosomonas bacteria also use ammonia or ammonium equally. The conditioner will handle the sudden influx of ammonia at the water change. Conditioners tend to give out in about 24 hours, but by then the plants and bacteria will be able to handle any excess ammonium.

i have been using Prime to detoxify water before adding to the tank and that should take care of the ammonia... and hopefully plants/bacteria are taking care or the ammonium afterward

Last point, the API test kit for nitrate instructs you to shake regent #2 for 30 seconds; in fact, it should be shaken for 2 minutes before adding the drops to the tube of water. Otherwise the results may be inaccurate, usually higher than the actual nitrate.

yup i saw on the forums that many people had problems with API nitrate test kit... i now shake the bottle more than 2 minutes before the test... i am detecting 20ppm of nitrate right now... i will be doing weekly water changes to take care of that


one question.... how long do you think i should wait before adding more fish to my tank

 

[Byron]

one question.... how long do you think i should wait before adding more fish to my tank

You are OK to add fish now. Don't overload at once, but adding a few as you find what you want will cause no trouble.

 

[mjbn]

I think you're doing fine with your tank. Nitrates mean it's cycling correctly, but just be careful with it.