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Nitrites starting to pick up, when should I do a water change?

5K views 32 replies 11 participants last post by  Tyyrlym 
#1 ·
Ammonia is starting to decrease so I'm assuming Nitrites will start picking up, when should I do a water change and what percentage?
 
#4 ·
Ammonia .25 down from .50

Nitrites .15
 
#5 ·
With fish, my signature should tell you which ones.
 
#6 ·
It's nothing but water changes when you cycle with fish. Get moving. start with about 20%, recheck and do more if they're still present. Your life now revolves around keeping those fish alive. It WONT hurt if you add a touch of superbac w/ each water change, yes its nitrifying bacteria and will help in a short time.Good luck
 
#7 ·
Agreed. When cycling with fish it's all about water changes. I cycled with fish (at the time I didn't know any better) and as soon as I saw a reading for amm. or nitrite is was instant water change on the spot. In my opinion none of my fish suffered during the process but it was very time consuming and I think I went through an entire API master test kit in the process, no joke. 20% is the volume I changed each time, and there were days on end where I did a 20% water change in the am and had to do another 20% in the pm. (Luckily it was a small tank and not a 100g plus). Stay on top of your parameters religiously and your fish will thank you :)
 
#8 ·
If I keep nitrites and ammonia at 0, won't that stunt/stop my cycling process?
 
#10 ·
As Burninator states, your fish are producing waste (ammonia) so your cycling progress will continue. Eventually your biological will increase to the point that it can handle the load your fish are producing. Once it reaches that point you can back off to once a week water changes. Keep on track with your water testing, performing water changes as necessary, and eventually your tank will cycle. Diligence & patience....:)
 
#13 ·
That's what I'm gonna shoot for :) thanks.
 
#12 ·
So true. I did water changes as soon as I saw .25ppm and a few times it hit .50ppm 12 hours after a water change..those were the days I was doing water changes 12 hours apart.
You just have to stay on top of it! You'll get there...
 
#15 ·
I would seriously consider not doing it. Results are hit or miss and a miss can dump a lot of dead decaying matter into the tank leading to an instant ammonia spike.

Water changes will not slow down cycling. Ammonia and Nitrite that you detect are excess that the bacteria cannot consume so you're not hurting them by removing some of it.
 
#16 ·
I agree with Ty, If these so called bacteria in a bottle produced the desired results for everyone then word would spread like wild fire accross the internet and places that sold these snake oils,,errr,, products would not be able to keep it on their shelves.Too many different variables come into play for these products to work equally well for everyone.
Were it me,,, (and it ain't) I would use NOTHING in my aquarium other than a dechlorinator that detoxifys,,ammonia, chlorine,,and chloramines. PRIME is the product I use as well as many others.
 
#20 ·
One more thing. Many people ask how much water to change. When cycling a tank you need to keep some amount of ammonia and/or nitrites for the bacteria to feed on so they multiply. That's of course why you don't change all the water or too much. But how much should be changed? That depends on how much ammonia the fish are producing per day, the size of the tank and the stage at which the cycling is at. But the point I wanted to make is simple.

If you want to lower a given reading by half you change half the water. Lowering by 25% would require changing 25% of the water. So by monitoring daily or every other day, you should be able to tell how quickly the ammonia and/or nitrite values are increasing and be able to tell how much water to change.

Here's a couple of guides

http://freshaquarium.about.com/library/begin/xcolorammoniachart.htm

http://freshaquarium.about.com/library/begin/ncolornitritechart.htm
 
#22 ·
It's up for debate, but I believe keeping your ammonia and nitrite levels as low as possible *can* prolong your cycle.

But, since you have live fish in the tank, keeping them happy and healthy is of utmost importance. I'd rather make my cycle take twice as long and have my fish live through it than kill them off trying to make the tank cycle faster.
 
#23 ·
No Nitrites Yet :(

Just as I thought ammonia might be lowering (as you can see in my other post)...it didn't and I just did a 50% water change to reduce it from .50 or so to .25.

My Question:

Was a little concerned about when my nitrites might pick up. I am not using any "quick cycling" products such as bio-spora but it's been exactly 11 days and I still have no readings of nitrites. Should i worry?
 
#24 ·
No, it'll take some time. The initial colonies take time to grow, things will speed up and happen faster.

It's up for debate, but I believe keeping your ammonia and nitrite levels as low as possible *can* prolong your cycle.
I'm curious as to why you believe this. Not trying to pick a fight, just curious.
 
#25 ·
It would be impossible to measure all of the variables present that determine beneficial bacteria growth rates. The supply of ammonia (or nitrite, depending on the bacteria) is only one of these factors, and probably the only one we can measure reliably. If one of the other factors were to change, there could be potential for the bacteria to multiply at an increased rate. At that point, the supply of ammonia or nitrite in the tank would be a limiting factor on bacteria growth rate. If you had a higher concentration of ammonia, the bacteria would have been able to multiply faster.

As I've said before, all of that doesn't really matter much. If you're cycling fishless, there's really no point in doing water changes anyway since that's just extra work and costs extra resources. If you're cycling with fish, you absolutely want to be doing water changes to keep ammonia and nitrite levels low for the benefit of your fish.
 
#26 ·
I see what you're saying but I don't agree. Detectable ammonia and nitrites in the water are materials the bacteria cannot consume at the moment. While multiple conditions can affect bacterial growth many of the big ones are highly stable in an aquarium, the temperature isn't going to vary by more than a degree or so, pH is steady, flow is steady, etc. The only thing that's changing is ammonia or nitrite in the water which is built up excess that they cannot consume. The bacteria are already consuming food and making more bacteria as quickly as possible. While there could be other factors we don't monitor that are changing in a semi-closed system like an aquarium they are minimal.

Since what we're looking for is a sufficent number of bacteria to consume the ammonia and nitrites at the rate they are created in the aquarium a sudden dramatic rise in the number of bacteria to a level sufficent to consume 0.25 or 0.50 ppm of ammonia or nitrites rapidly would be the tank finishing cycling. If the bacteria populate enough to consume all the ammonia present in a tank your tank has cycled. If there are not enough to keep up with the fish they will not be able to eat themselves out of house and home because they will never able to keep up with production.

Look at it this way. Your tank is a table. A conveyor belt is bringing a constant stream of food to the table. A guy is sitting at this table eating as quickly as he can. The downside is to begin with he can't keep up. The food starts to back up on the table. New guys get added to the table from time to time but the food keeps piling up. Eventually someone comes along and takes away half the food piled on the table. Well the food doesn't stop coming, and the guys don't stop eating.

Here's the thing, the pile of food on the table, the ammonia and nitrite in our tanks, they're byproducts of what's really important. What's important is that conveyor that's bringing food to the table. If the guys around the table can keep up with it no food piles up. If they can't the food will pile up no matter how much of the excess you remove. I can remove 99% of the food from the table, but if the guys around it can't keep up with the conveyor they still won't be able to clean the table off. You see the conveyor keeps working at the same speed no matter what. It doesn't care what happens on the table, it keeps bringing the food. In our fish tanks our fish don't care what's happening with the ammonia levels. They keep on breathing, eating, and pooing no matter what. Their production is constant, until you have enough bacteria to consume all that waste they will never be able to remove all the ammonia and nitrites from the water.

Therefore water changes make no difference at all on cycling the tank. If you don't have enough bacteria ammonia levels will alway be > 0 and always on the rise. If you have enough bacteria to consume all the waste being made then guess what, it's cycled.

Like you said though, this is mostly academic because it makes no difference to fishless cycling where there are no fish requiring you to keep ammonia levels down. I do think it matters somewhat though because I have heard people hold off on water changes with fish-in cycling, or advise holding off on them, specifically to keep from prolonging a cycle. I think it's worth pointing out that it doesn't, and to keep on with the water changes for your fish's health.
 
#27 ·
Therefore water changes make no difference at all on cycling the tank.
Using your analogy, water changes is like having someone from the restaurant coming in to remove half the uneaten food from in front of the guys. It will slow down the introduction of new guys because the guys that are there may not call in friends to help them eat. And since the conveyer belt is still bringing a constant supply of food, you want to encourage new guys to arrive. But more importantly, if the food backs up enough, the eaters will start to suffocate in all the food they are sitting in. (fish dying)

But you do want to keep more food in the room than the guys can eat so new guys arrive yet you don’t want to starve the guys you do have.
 
#28 ·
Except for the fact that there is still excess. Water changes, unless they are 100% water changes, can never remove all the excess pollutant in the water. Also, until your tank is cycled the conveyor continues to bring food faster than it can be eaten which means that even if you do a 100% water chance there will immediately be an excess of pollutant in the water because there are not enough bacteria to keep up with its production.

So there is always an excess of food for the new bacteria baring a total water change. Remember what we're dealing with her, microscopic bacteria, unicellular organisms. 0.1 ppm of ammonia might not seem like a lot, it might seem like there's not enough food to support new bacteria, but we're talking an amount of excess ammonia in the water that is thousands of times more massive than the bacteria and its getting greater all the time.

Since you can never remove 100% of the excess pollutants from the water by doing water changes the only way to get 100% out and actually start to starve bacteria is by the bacteria themselves consuming all the available excess pollutant. That's not a bad thing, it's a cycled tank.
 
#29 ·
But if you remove 99% of the food on the table, and all you have left at that exact time slice is a single grape, that's not going to attract another guy to the table. Bacteria multiply by doubling; a single bacteria may not reproduce if there isn't enough excess ammonia in the water for it to warrant reproduction. Yes, there is always excess in the water, but I also believe if there is little enough of this excess bacteria may not multiply at the same rate they would if there was *more* excess.
 
#30 ·
All this talk about food on the table is making me hungry!!! All my (fish in cycles) were complete in about three weeks, with a lot of water changes. I am now three weeks into my fishless cycle. My nitrites are off the chart, I am guessing it will take quite some time for them to drop down to zerro. This cycle is going to take alot longer, but my hopes are that by doing it this way, I will create a very large amount of bacteria and be able to introduce 8 or 10 fish at one time.
 
#31 ·
I see what you're saying but the analogy has some problems. The first is that the mass of the food in the water is enormous compared to the bacteria. I'm working on getting a piece of data I'm missing, the mass of an average cell, but suffice it to say that even 0.10 ppm of ammonia in an average aquarium is a tremendous amount of available food for a bacteria. Second, my analogy prompts images of a conveyor delivering discrete packets of food at regular intervals so that there is a chance if you remove all the food from the table (a 100% water change) you get the idea that someone might reach for a piece of food and find none before the conveyor brings something else to eat. This isn't the case. Ammonia production in the aquarium is for most part a continuous function. It's more like a conveyor spilling a stream of rice onto a table or a hose spraying water than a conveyor bringing steaks.

1) I reiterate, if the bacteria can consume the excess ammonia in the water then you have a cycled tank. Excess ammonia in the water represents a tremendous excess of food. Most of us are familiar with the cycling graph. Here's the thing, the point where the amount of ammonia in the tank ceases to increase is the moment you have sufficient bacteria present to deal with the ammonia production of the inhabitants of the tank*. Same with nitrite. When the amount stops increasing you have enough to support your tank's inhabitant. The rate the bacteria are consuming the food in the tank is equal to the rate its being created at. Any bacterial growth beyond that represents overpopulation to deal with the excess.
2) Bacteria are consuming pollutants in the tank as quickly as they can at all times. Bacteria aren't like humans, they won't stop eating because they're getting fat or because they're full. They eat everything they possibly can and reproduce as fast as they can. Therefore excess nitrogenous substances in the water represent food that absolutely can not be consumed at the moment by the current bacteria. The bacteria consume the amount of food they can, it doesn't matter how much is present beyond that amount, it makes no difference to the bacteria.
3) The mass of ammonia in a 50 gallon tank with 0.10 ppm ammonia is approximately 30,000,000,000 (30 billion) times more massive than a single bacteria. There are of course far more than just one bacteria in your fish tank but even if you have 3 trillion bacteria in your tank each individual bacteria has 1% of its body mass of excess food available on top of the continual production that is part of the tank. To give some perspective that's like your average man having a hefty steak dinner with all the trimmings on the table in front of him to work on while even more is being brought. Simply put, even at 0.10ppm ammonia (which my API test kit won't even measure accurately and represents a 60% water change when your ammonia is at 0.25ppm) there is still a lot of food for the bacteria in the tank.

Based off what I know and what I've seen it is my opinion that water changes during cycling have no negative impact on the length of the cycling process.

*Obviously this mostly has to do with fish in cycling which is a far more precise process than fishless cycling. Fishless cycling is easier on fish but not very precise in terms of the size of your bacterial colony at the end. That's why it is CRITICAL that if you fishlessly cycle you take the addition of stock slowly and carefully. You CAN NOT fully stock an aquarium immediately after finishing a fishless cycle.
**My math in this is based of an approximation of the mass of a cell, 0.6 picograms. I was unable to locate the mass of a nitrifying bacteria so I took used the mass of an average sized bacteria.
 
#32 ·
But, as you stated, bacteria and people are very different animals. True, bacteria don't get "full" and stop metabolizing, but they may also have chemical triggers that say, "only reproduce when there is a certain concentration of available food in the environment" that aren't being satisfied if ammonia/nitrite levels are kept as low as possible. We'd have to ask a cell biologist to be sure.
 
#33 ·
Yes we would. If there is such a trigger though I am thinking the threshold must be extremely low. So low that we can't detect the ammonia level that remains in the tank. The lowest level of excess I'm suggesting is maybe 0.10 ppm which you'd only see after a very aggressive water change at a 0.25ppm concentration of pollutant. If super low concentrations of pollutant inhibited bacterial growth I'd think we'd see some evidence of it, specifically when cycling with fish. As best I can see however there isn't any significant difference in the time it takes to cycle with fish, doing appropriate water changes, as it does to cycle fishlessly where pollutant concentrations are 20 to fifty times anything you'd see while cycling with fish.
 
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