View Full Version : New tank cycling question

02/09/2009, 11:06 PM
Hi guys.
I'm totaly new to this hobby and have no idea where my cycling is at. I have an 80 gal tank (probably about a 100 gal with the sump), it's been with the live rock (80 pounds) and live sand for about 5.5 weeks. At the beginning I had some lame test kits and couldn't read my ammonia levels properly. After a couple of weeks of struggling with it I finaly broke my vial and didn't test the ammonia for a week or so at all. Finally got a better one ( it's Tunze and I do think it's readings are quite accurate) and have been checking my parameters daily for a week. My ammonia has been stubbornly stuck at 0.2. It's not going up, it's not going down. Nitrites have been at 0 all the week, nitrates - at 20. I want to add about 30-40 more pounds of fully curred live rock after the cycling is done, but it doesn't seem to move anywhere. Is it still cycling? Or can ammonia spyke, go down and start building up again because it needs a water change? I have no animals in my tank (except an army of copepods). Some of the purple sponge looking growth on the rock has died off (not too much of it though), the rest of it went through a "dull" phase and looks all happy now. Where do you think am I at in the cycle? Thanks!

02/09/2009, 11:25 PM
It sounds as if you are still in the early stages of the cycle. Some systems take several months to fully cycle. It sounds as if you still have some dieoff happening that is causing the ammonia spikes. Keep checking and be patient. Water changes will help keep ammonia levels to a minimum. You will know the cycle has finished when your ammonia and nitrites are consistently 0.

02/10/2009, 09:28 AM
just be patient and you will be rewarded. Patience....

02/10/2009, 10:04 AM
You can always take your water to a couple LFS to be tested as well. That way you can know if it is your test kits, but it sure seems like it is cycling

02/10/2009, 10:16 AM
I'd try to check your ammonia reading against another test kit; taking it to your LFS might be a good way to go. Ammonia tests are notorious for giving false readings at the low end.
Zero nitrites and an army of pods suggests your cycle MIGHT be finished, but you need to be sure about that ammonia reading.

02/10/2009, 10:26 AM
Are you sure that the new rock you will add is truely "fully cured". Chances are you will go through another mini-cycle when you add it to your tank. Unless there are some fragile lifeforms on the new rock that you are worried might not make it through a cycle, I'ld add the new rock now and save the time of going through an additional cycle.

02/10/2009, 11:00 AM
<a href=showthread.php?s=&postid=14362549#post14362549 target=_blank>Originally posted</a> by thegrun
Are you sure that the new rock you will add is truely "fully cured". Chances are you will go through another mini-cycle when you add it to your tank. Unless there are some fragile lifeforms on the new rock that you are worried might not make it through a cycle, I'ld add the new rock now and save the time of going through an additional cycle.

I'd add the extra rock now as well. Also, double check your results with your LFS. Most of the time, they will do the tests for free.

02/10/2009, 11:20 AM
What kind of filtration are you useing? Do you have a protein skimmer?

02/10/2009, 08:14 PM
Thanks everyone for the advice. Well, the amonnia went up to 0.5 today. I guess my tank overheard me complaining about him and decided to start moving:) . Another change - started to get golden/brown algae on a few of my rocks. Should I do a water change or leave it alone for right now? I just kept the lights off all day, hoping it would slow it down.
Ranchhand02, I have ASM G1X protein skimmer.

02/10/2009, 08:25 PM
WOW, took 6 weeks to start the cycle? My guess is there was no dieoff from the original rock batch hence no ammonia introduction. Guessing adding the other rock you had - had dieoff, introducing the ammonia, activating A cycle. keep a good eye on the ammonia params, with the new "bioload" (dieoff on the added rock) it may have just been a large shock to the bio, hence the ammonia reading, the bio may catch up shortly.

02/10/2009, 08:28 PM
IMO, Don't do a water change and don't leave the lights off.
The light promotes the growth of the algae and brown diatoms that are helping process nitrogen out of the tank. It'll give your clean up crew something to eat later ;)
Let the ammonia spike up to at least 1.0 if it will. If it goes higher than that consider a partial water change just to keep it from killing more beneficial life in/on your rock.

02/10/2009, 11:14 PM
Mariner, thanks for the advice. I'll do as you said.
Stricknine, you missunderstood me. I've never put the second batch of the rock in ( I posted my question yesterday only). This is the same rock and it will be six weeks old in two days. I can not comment on the quality of it since I'm totally new to this. But it had a LOT of purple sponge looking growth on it once I got it. It even came with a beautiful 1" by 3/4" purple sponge, that I identified online as a Red Lumpy Spone (Monanchora unguifera). Internet says it is not sustainable. You would think at least that one must have died quickly. Nope. Shows no signs of distress so far :).

02/10/2009, 11:27 PM
...Hmmm... I dont understand why you dont add the rock all at once. If you wait, then add it later you will end up with another mini cycle...after the mis-understood cycle already?

IMO. add ALL the rock, Amonia up, then nitrates up, then nitrites up, let it all settle to zero, and plan from there.

02/11/2009, 12:07 AM
Stricknine, it was just a mistake of mine. When I was first buying the rock, my LFS guys had some beautiful Tonga rock that they took out of their own show tank. It was a few years old and very pretty. They suggested buying some precured rock first, cycling it, and then adding some of the expensive one. But I don't think they even have any of it left by now. So I'm sure you're right - I'll end up with another mini cycle.

02/11/2009, 07:55 AM
Kriste, I disagree with mariner on when you should do a water change. I recommend doing one every few days as long as there is any testable ammonia. Ammonia is extremely toxic and allowing it to accumulate doesn't speed the cycle along. The bacteria are already growing close to their maximum rate and the reason you have measurable ammonia is because it's going unused.

02/11/2009, 10:12 AM
I'm sure you are right about the bacteria growing near max potential if there's measurable ammonia at all, and that the excess is there because the bacteria aren't there in sufficient amounts to process it. We leave some ammonia present to spur the bacterial colonies to grow. In a perfect world we would keep ammonia levels at exactly the levels the bacteria need at the moment. Obviously, we can't do that. There needs to be a little more ammonia than the bacteria can use during a cycle. The question is, "How much more?"
I pass on the advice "do a partial water change if it reaches 1.0" from guys like Fenner who have probably observed the cycling of 100's of tanks. Have they observed under a microscope how much micro life is being destroyed at comparative levels of ammonia (e.g. .25, .5, 1.0, 2.0)? Maybe, but probably not. They just know what they've seen work.
With all that said, you may be entirely right, you're the marine biologist. :D I just try to pass along what I've read from those with more experience than me, and from my own experiences.

02/11/2009, 03:20 PM
Hey Steve,
It helps to think about what's going on in terms of population ecology and what's actually happening with the bacteria. Hopefully this isn't too confusing.

When you have measurable ammonia, that means it's in excess for the current bacterial population. It's not limiting growth. Increasing it more doesn't affect the growth rate since it's not the rate-limiting resource anyway (until you get close to the carrying capacity).

What the ammonia level does do is affect the carrying capacity like you pointed out. The tank can't support more than it can feed. You can increase the ammonia and it will increase the carrying capacity, but once you remove that ammonia source the carrying capacity drops back to what the tank produces constantly (aka the bioload). When ammonia production drops back to normal the bacteria don't just hang around waiting for for a new ammonia source. They die. Spiking the ammonia during the cycle artificially raises the carrying capacity temporarily and sets up fluctuations around the eventual carrying capacity so that it takes longer for the population to settle down or has hobbyists talk about it- longer for the tank to "mature." Minimizing the spike causes the population growth to slow down before it reaches the carrying capacity so it approaches gradually and doesn't overshoot much.

Here's a cheesy little graphic I made a while ago to show the difference between the two schools of thought:

02/11/2009, 04:04 PM
Thanks Mike. Very educational, despite the cheesy graph ;)
Obviously both methods wind up at the some point, but no water change has more fluctuation, and that can't be good. Of course, I wasn't advocating no water change, just using 1.0 as the point at which you do them. I think I might alter that advice :D
thanks again,

02/11/2009, 08:32 PM
Thank you, greenbean36191. It's a very useful information.


05/05/2009, 10:30 PM
Hi everyone! Hope everyone is doing well.

It's been awhile since I've posted. You guys were very helpful and I figured I should give an update on how things are going.

Just a quick reminder - it took for ever (6 weeks) for my tank to start cycling. Once ammonia finally spiked, it stayed at around 0.6 for 5 days. Then it dropped to 0.4 and stayed there for about 10 days. I barely saw any movement in nitrites/nitrates all that time. On the 9th week it dropped to 0.3 and... got stuck there again.:). Tried to do water change, tried not to - nothing worked. It kept sitting at 0.3. Then, on the 15th week, I got a new test kit ("Salifert"), because the old one ("Tunze") was about to expire. Measured ammonia and it came back at a 0. The interesting thing is "Salifert" considers it a 0 if it's bellow 0.25. "Tunze" gives you a color sample for 0 / 0.2 / 0.3 and it's a BIG difference between those three (high resolution). I guess "Tunze" is just very very accurate. By the way, "Tunze" still measures 0.2, but it has expired last month.

So by the time I realized i had 0 ammonia, my tank was 14 weeks old. It was full of all kinds of little critters: copepods, amphipods, spaghetti and bristle worms, brittle stars, etc. I added about 30 more pounds of fully cured live rock, then some cleaners and a couple of Nemos for my 1.5 year old daughter a week after. The new rock came with some kind of a purple mushroom anemone, who doubled it's size in the first 10 days and now has a little sister or brother.:) The shroom came hanging on the rock like a slimy bugger and I wanted to scrape him off thinking for sure he was dead, but I lost him. He's a suvivor!:) Unfortunately, new rock came with a Mr.Clicking Noise Maker that we'll try to set a trap for this weekend. I"ve been missing both of my Peppermints for three days now, had a snail and a crab die. And I'm also getting the cyano algae.:((

So that's where my first reef tank is at.:) It is becoming very interesting.:)

This is the set up:


Thanks everyone for helping me to get here!:)


05/06/2009, 12:14 AM
Next time use 3 raw shrimp in a nylon stocking and your ammonia will spike in a few days.