Stalled Cycle – Why Is My Marine Aquarium Taking So Long To Cycle? - A Helping Hand

Welcome to Simple Reefs. This is a brand new website dedicated to taking the complexity out of Marine Aquarium Ownership. Our goal is to show you how you can own your very own slice of the ocean without spending a fortune. As well as giving you tons of easy to digest information on all things marine. We have been talking about aquarium cycling a lot, lately. Which leads us, perfectly, on to a question that many new owners may have regarding stalled cycles. Why Is My Marine Aquarium Taking So Long To Cycle?

Believe me, I have been in this situation and it is frustrating. I went into this hobby ready to endure all the waiting in the world to make sure I got the results that I wanted. Despite this, as the six week mark passed and my marine aquarium still wasn’t done cycling. I started to get a tiny little bit sick of staring at it in all it’s baron, uninhabited, drabness. If felt like it was never going to happen. But what are the reasons that this can happen? What is a stalled cycle and what can cause your marine aquarium cycle to slow down?

Why is My Aquarium Taking So Long To Cycle?

As we discussed in our previous article on what cycling your aquarium means. The process of cycling your aquarium involves the establishing of a bacterial profile in your tank that is capable of converting toxic ammonia, from food and waste, into the less toxic compound nitrite before, finally, converting the nitrites into the even less toxic compound nitrates.

The way we do this is fairly simple and we will cover it completely in an upcoming article. It, basically, involves adding a source of ammonia to the aquarium, rotting food or ammonium chloride, and allowing the bacteria in the aquarium to consume the ammonia. This will cause the bacteria to reproduce, or split, in a process known as binary fission. Eventually doing so to a point where the bacteria will cover the surfaces of your aquarium (rocks, sand, etc). Making the tank safe for residents.

It all seems pretty straight forward, right? Almost as if it is impossible for it to go wrong. Well, unfortunately, that just isn’t the case. There are a number of different ways in which this process can slow down considerably, resulting in what a lot of people refer to as a stalled cycle. The good news is, the cure for this problem is, almost always, very straight forward. Keep doing what you are doing and take it slowly.

What is a Stalled Cycle in a Marine Aquarium?

A stalled cycle is something you may have read people discussing on forums regarding aquarium ownership. In fact, it is quite a common topic. The reality is, however, a stalled cycle isn’t actually a real thing. We still refer to it as a stalled cycle but, in actuality, your cycle isn’t “stalling”, so to speak. Your cycle never actually stops completely. It is just taking some time to do what it is doing.

Bacteria are living organisms and, like most living organisms, they like things a particular way. Just like that house plant that needs watering once a week and won’t seem to grow unless it is kept in that one particular spot by the window. Bacteria will only thrive when conditions are optimal.

Sure, it will still convert ammonia and will still split. It will just do it at a much slower rate. While it can seem as though your cycle isn’t progressing. You may just have hit a point where the conditions for the bacteria aren’t quite optimal and they are taking a little longer to reproduce than you initially expected.

We Need Optimal Conditions for Bacteria

The bacteria that converts ammonia to nitrite, Nitrosomonas, takes six to ten hours to double in numbers… In optimal conditions, that is. So that means when ammonia levels are ideal, temperature is ideal, PH levels are perfect, salinity is spot on, oxygen levels in the water are good, etc. Any variance in those factors will make this process take longer. A much more realistic time period is 16-24 hours.

It is difficult to provide these optimal conditions; this is especially true in a new aquarium. If we overload the bacteria with ammonia, it will take longer to process the ammonia and longer to double in numbers. Making it seem like our cycle has stalled when, in reality, it is just slowing down a little. We can fix this by attempting to provide those optimal conditions for the bacteria. In effect, speeding up the process.

But what situations may suggest that our cycle isn’t going quite how we want it to and we might be experiencing a stalled cycle? After all, there aren’t going to be too many visual hints. Aquarium cycling doesn’t exactly have too much in the way of visible changes to indicate how it is going. We are going to have to get our test kits out to see for ourselves. This will bring us to one of a few different scenarios that we are going to look at here.

How Will I Know I Have a Stalled Cycle?

There are a few things that will indicate that your aquarium cycle isn’t progressing as quickly as you may want it to and that you might have a stalled cycle. The majority of indicators come in the form of test kit results.

The biggie is, obviously, ammonia testing. When you take that sample of water each, and every, day; only to see it repeatedly come back positive for ammonia and slowly start to feel your enthusiasm for this hobby wain. There are a few different reasons that may lead you to believe you have a stalled cycle, however, including..

• Ammonia levels won’t drop or are dropping very slowly.
• Nitrite levels won’t drop or are dropping very slowly
• Nitrate levels are very high.
• Nitrate levels are very low or non-existent.
• No algae growth.

So we are going to immediately discard that last one. Though algae growth can be a strong indicator that our aquarium cycle is doing well. It’s not an essential prerequisite. Simply keeping the lights off may mean you experience virtually no algae growth. Don’t ever use this as an indicator that you are experiencing a stalled cycle.

The other bullet points in the list are more significant but there is some very good news. There is only one of those points that actually suggests that you have a stalled cycle and that is the first one. The others are, really, fairly insignificant. We tell you exactly why in upcoming articles and we, also, show you how to fix a stalled cycle. If you are experiencing any of the problems listed there, feel free to click the links to check them out.

Why Am I Experiencing a Stalled Cycle in my Marine Aquarium?

Well, unfortunately, this is one of those annoying “how long is a piece of string” type of questions. It is hard to know without knowing the specifics of your setup. Take a look at our article on the reasons you may be experiencing a stalled aquarium cycle for more answers.

To quickly summarise, your aquarium cycle never actually stalls. It just takes longer to do what it is doing thanks to less than optimal conditions. We can rectify this by creating better conditions for our bacteria to speed things up. Thanks for reading and spending your time on Simple Reefs.