Cycle Problems

[Bill]

A nickel to whoever can help me...

 

About five weeks ago I started adding 10% ammonium hydroxide (from Ace Hardware) to my 100 gal tank to begin a fishless cycle. About 3 weeks later the ammonia levels would drop down to .5ppm in a day after adding it to ~4ppm and the nitrite levels got VERY high, to the point where the API test tube would turn blue-grey, which I later found out indicated a very high nitrite level. I then read that a very high nitrite level could stall the cycling process. At this point my Nitrate levels were relatively low--in the 5ppm range. I read that a large water change might help put the cycle back on track so I did a near complete (>95%) water change. My nitrite still measured very high (in the 5+ ppm range) so I did another very large water change the next day. I siphoned the water until the nitrite reading was zero. The nitrite and nitrate reading were also zero. I then added ~2ppm of ammonia and it took about a week for the ammonia to go from 2ppm to ~.5ppm, but the nitrite levels began reading 2-4ppm at about day 3 or so. Then the nitrates started reading between 0-5ppm. About 4 days ago I added ammonia to ~ 4ppm and it is still at that level currently. The nitrite level is off the chart (5+), my nitrates are SLOWLY increasing and are currently at 5ppm, but my ammonia doesn't seem to be lowering (still at ~4ppm).

I keep the pH between 6.8-7.6 (mostly ~7.3). The temperature is between 88-94F. The system is a constant flood and drain with a 50 gallon grow bed filled with hydroton (similar to Murray Hallam's, but smaller). I am pretty sure I killed off most of my bacteria with the water changes I did-- I did not use purified water, as buying 100 gallons of purified water would not only be costly but impractical to lug around. So my question is: if nitrite and nitrate levels began rising less than 3 days after my water change, then why does it seem as if my ammonia level is falling disproportionately slower? I've heard that the rise in nitrites and nitrates when compared to the fall in ammonia may not be exactly proportional, but can someone explain to me if this is normal and how long it will probably take from here on out (IT'S BEEN OVER 5 WEEKS ALREADY!!). Also, seeing how my nitrites are very  high again, it seems as though I am back at square-one and the water change that slowed me down was all-for-nothing. Once and for all can I get a straight answer: does having a high nitrite level REALLY stall a cycle?? I dont think I'm going to do another water change and risk this whole ordeal again so I'm hoping the answer is no.  

[Eric Warwick]

Your fine. 

Bill said:

I've been using phosphoric acid to lower the pH and potassium hydroxide and calcium carbonate to raise the pH. Do you think the phosphates from the acid may become a problem for the fish or is that not much of a concern? I've been adding about 1-2 ml/day over the course of the week because the pH was buffered from the CaCO3, but I think the pH finally leveled off (somewhere around 7.0-7.2). Thanks!

[Bill]

Ok so my nitrate levels have shot up from 5ppm to about 35-40ppm and my ammonia levels have dropped to zero. I'd say the ammonia has been at zero for about 2 days or so (I haven't added any as I wait for the nitrites to drop). The nitrite levels are still 5+ppm, but I am assuming they will start to show a decrease considering the increase in nitrate. My question is: should I wait until the nitrites go from 5ppm to 2ppm to add a little ammonia or wait until all of the nitrite is brought down to zero? Also, will not adding ammonia "starve" the nitrite-producing bacteria; how long can I go without adding ammonia to my system before I start to starve that bacteria? Thanks for your help, your advice has proven to be very helpful so anymore would be greatly appreciated!

TCLynx said:

Are you dosing with ammonia daily?  or just that one dose?

 

If you are dosing with ammonia daily, STOP, wait till the nitrite drops, having too high an ammonia level can inhibit the bacteria that convert the nitrite to nitrate.

 

I've cycled several systems and I usually don't dose the Ammonia that high and if the nitrite gets too high, I stop dosing the ammonia until I see the nitrite dropping.  Once the initial nitrite spike has passed, you then dose the ammonia and then measure the ammonia and nitrite 24 hours later, once you get to the point that you can dose ammonia one day and have both ammonia and nitrite get to 0 24 hours later, you are fishlessly cycled.  At that point you can keep up with small doses of ammonia to keep the bacteria going until a day or two before you will bring home fish (you want to make sure both ammonia and nitrite are down before you bring your new fish home.)

[TCLynx]

I would say wait till you can see a drop in the nitrite before you dose any ammonia but if the nitrite is still above 2 ppm then make it a small dose of ammonia.  Once the nitrite drops to 0 go ahead and do a full dose of ammonia and see how long it takes to process from there.

Also watch the pH since many times you might see a sudden pH drop about the same time as a sudden nitrite drop.

[Jonathan Kadish NYC AA Chair]

TC what is a good initial dose? I am just about to cycle my system and it is only 26 gallons.

TCLynx said:

I would say wait till you can see a drop in the nitrite before you dose any ammonia but if the nitrite is still above 2 ppm then make it a small dose of ammonia.  Once the nitrite drops to 0 go ahead and do a full dose of ammonia and see how long it takes to process from there.

Also watch the pH since many times you might see a sudden pH drop about the same time as a sudden nitrite drop.

[TCLynx]

Depends on what you are dosing with I guess.

 

A good initial dose (provided you have neutralized any chlorine or chloramine first) would be somewhere between 1-4 ppm.

With a 26 gallon system it won't take much of most anything to get an initial ammonia level that is high enough to get things rolling.  (I've cycled a 50 gallon system using doses of like 50 mil of aged hummonia before.)  So if you are using pure cleaning ammonia you will probably be adding much smaller amounts per dose.  I think Sylvia has a blog post about the mystery of the missing ammonia that might have some helpful clues to figure out how much you might use to get the right dose.

[Jonathan Kadish NYC AA Chair]

Tiny amounts ... got it.

TCLynx said:

Depends on what you are dosing with I guess.

 

A good initial dose (provided you have neutralized any chlorine or chloramine first) would be somewhere between 1-4 ppm.

With a 26 gallon system it won't take much of most anything to get an initial ammonia level that is high enough to get things rolling.  (I've cycled a 50 gallon system using doses of like 50 mil of aged hummonia before.)  So if you are using pure cleaning ammonia you will probably be adding much smaller amounts per dose.  I think Sylvia has a blog post about the mystery of the missing ammonia that might have some helpful clues to figure out how much you might use to get the right dose.

[Bill]

Ok I'm almost there! (Thanks to TC and Co.)  My system went from ~2ppm ammonia to <.25 ppm nitrite in 24 hours. I dosed again and we'll see if it's finally fully cycled tomorrow. I have 2 questions:

 

The nitrates are getting high (~80 ppm and rising) and I was wondering if I can add plants at this level or will this amount burn the roots?

 

Before I add fish, do I have to do a large water change to lower the nitrate levels or is there another method--about how long will plants take to remove the nitrates to a safe level for the fish? I'm assuming there must be a way to lower nitrates without doing a large water change because it wouldn't be practical for people who have tank water or very large systems to do such a large water change. I have chlorine in my tap water so I'd have to use some type of purified water and it wouldn't be economical to siphon out 65+gallons and replace that amount with purified/reverse osmosis water.

 

Almost there, thanks for all your help!

[RupertofOZ]

Plant your plants... and let them suck up the nitrates...

 

Add your fish, don't worry about the nitrates... and don't water change...

[TCLynx]

I agree.  Get the plants in there and avoid the water changes.  I regularly run high nitrate levels on my big system and it doesn't seem to affect the fish at all.

[Bill]

Thank you everyone who replied. The tank is officially cycled and I added the plants this morning! Woohoo!