Stalled Cycle – Do You Have Enough Surface Area For Bacteria? - A Simple Solution

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 are still talking about stalled cycles and, today, we are asking a simple question. Do you have enough surface area for bacteria?

We have been talking a lot about marine aquarium cycling, recently. Which, naturally, has brought us onto the subject of stalled cycles. The bane of many a new marine aquarium hobbyist’s existence. A stalled cycle can leave you feeling distraught and a little bit lost. Especially when it comes to the cause of the problem. After all, there are so many reasons why an aquarium cycle might slow down and grind to a halt.

When examining the reasons for a stalled cycle. One of the things that came up was surface area for bacteria. A potential cause that I think a lot of people overlook. Especially those owners who have chosen to start a marine aquarium without rocks and sand. If this is you and you are experiencing a very slow cycling process. Read on.

The Nitrogen Cycle in a Marine Aquarium

We talked about cycling a marine aquarium in our opening article on this subject but allow me to quickly recap. After all, the importance of the nitrogen cycle (Wikipedia Article) to a healthy marine aquarium can’t be understated.

In cycling our aquarium, we are establishing a bacterial profile, in our tanks, that can process harmful compounds like ammonia. Without the presence of these nitrifying bacteria, ammonia would accumulate and poison our aquarium’s residents. We do this by, simply, adding a source of ammonia in the form of liquid ammonium chloride, fish food, or a piece of frozen shrimp.

The ammonia from the liquid ammonium chloride, food, or shrimp, is converted into a less harmful compound called Nitrite by a type of bacteria known as Nitrosomonas bacteria. The Nitrosomonas bacteria doubles in numbers, effectively, every 16-24 hours. Once Nitrites are present in the water, a new type of bacteria will grow that can convert those nitrites into the even less harmful compound known as Nitrate.

Once we have nitrates in our water, the nitrogen cycle is complete and our aquariums are, in effect, cycled and it is now safe to add a fish or two. Pretty simple but what happens when that process suddenly appears to stop? We are adding ammonia every day but the ammonia levels stubbornly refuse to drop? Our cycle appears to have stalled.

Well, if you have rocks and sand, you may want to take a look at this article to find some answers. If, however, you don’t have rocks and sand and you started with, essentially, an empty aquarium. It is time to read on because the reason, and solution, may be pretty simple.

Not Enough Surface Area For Bacteria

It might sound stupid but it does bear mention if you are running an aquarium with filtration medium, no rocks, no sand, and minimal equipment. Do you actually have enough surface area for your bacteria to populate? After all, bacteria needs a place to live. A common misconception is that bacteria lives in the water column but this isn’t true.

Bacteria, actually, makes its home on, and in, the surfaces of your rocks and sand. It isn’t free floating in your water column which is why water changes don’t have a massive impact on bacteria levels. This can lead us to a very specific problem in bare minimum marine aquarium setups. Where can the bacteria populate?

If you are staring at an empty aquarium with just water, this might be the reason your aquarium cycle has stalled. The good news is, this is a really simple problem to fix but there is one caveat. You need a filter, be it hang on back, in tank, a sump, or a canister filter. You absolutely have to have something that can pull water through and return it into the tank.

Increasing Bacterial Surface Area in an Aquarium Without Rocks or Sand

Naturally, prevention is the best way to avoid having to deal with a stalled cycle caused by lack of surface area for bacteria. Especially considering how long this problem can take to appear and to fix. So making sure you have adequate filtration media before you begin cycling is the best way to avoid this problem. But, if it has already occurred, we can fix it quite easily as long as we have a filter.

The reason we need a filter is that we need somewhere to put some filter media that is going to give our bacteria a place to live. It’s that simple! Hell, you can even place this filtration medium on the base of your aquarium if you like. It needs to have your aquarium’s water flowing over it so that the bacteria can populate it and the water can deliver the ammonia to the bacteria.

If you don’t own a filter or sump, I would highly suggest buying a hang on back filter as they are incredibly easy to accommodate, in most types of aquarium, and they are at minimal risk of causing problems like flooding, or the like. We are then going to be grabbing some specially made, highly porous, filtration media that our bacteria will then populate.

Highly Porous Biologically Active Filter Media

There are so many options for extremely porous filter media that is designed to be populated by bacteria, effectively becoming bioactive. These range from small bio-orbs, and similarly sized media of various shapes, designed for compact filters. Right up to larger marine blocks, for large canister filters or sumps, designed to provide the equivalent surface area to many KG of live rock.

Many are made from ceramic material that is designed to attract the bacteria and last for a long time. Others are, simply, broken down fragments of live rock that you can keep in a bag or just pile up on the bottom of your tank. The principle is always the same. Provide the bacteria with a lot of surface area to populate while taking up as little physical space in the aquarium as possible. Making these products ideal for hang on back filters and canister filters.

How Should I Fix My Stalled Cycle?

The process is quite simple so let’s lay out a plan of action. First of all, you are going to need to purchase some porous filtration media. Buy whatever you think will fit in your filter or whatever you are comfortable having on the bottom of your tank. I will have suggestions for this in the future but, for now, check out user reviews and see what others think. Maxspect have a range of different bio blocks in varying sizes so maybe give them a look.

We are also going to want to purchase some nitrifying bacteria. Nitrifying bacteria contains everything we need to get our cycle going. Including the ammonia converting bacteria Nitrosomonas and the nitrite converting bacteria Nitrobacter and Nitrospira. When combined with porous bio filtration media, we can fix this problem easily. Simply follow these steps.

• Stop adding ammonia to your tank via food, ammonium chloride, or frozen shrimp
• Perform a 25-50% water change to bring your ammonia levels down
• Add your porous filtration media to your filter, your sump, or to the bottom of your tank
• If using a filter, turn your filter off. Turn off any water pumps or flow
• If using a filter, pour some tank water into your filter and over the filtration media
• Add the bacteria from your bottled nitrifying bacteria, as instructed on the bottle, directly to the filtration media.
• Wait half an hour, or so
• Turn your filter or pumps back on

All of this is fairly self explanatory as far as actions go but I will explain exactly why we are doing things in the way we are doing them as it may be a little confusing. The first point, stop adding ammonia, simply means we are going to stop the cycling process for a little while. We want our aquarium to catch up on the ammonia that is already in the system

The water change is, again, to help the aquarium out. Reducing the concentration of ammonia and giving the bacteria that is already present less work to do to get back to a neutral level of ammonia. We aren’t going to carry on cycling the aquarium until our current ammonia levels drop to zero.

Getting The Bacteria Straight To Where It Is Needed

Obviously, we are adding our porous filtration media to our aquarium, be it in a sump, a canister filter, a hang on back filter, or on the bottom of the tank. This is where the process differs slightly.

If we have a canister filter or hang on back filter, we are going to turn it off and then add some aquarium water to the filter. Go ahead and pour it over the filtration media but leave some space so it doesn’t overflow. You will probably hear it hissing thanks to how porous it is.

We are then going to dose our bottled nitrifying bacteria, as instructed on the bottle, directly to our filtration media. It may need mixing with tank water so observe the directions carefully. You want to pour it onto the filtration media because the bacteria will make disperse all over it, making its home there immediately.

This is known as “seeding the media“. The seeds being bacteria that will grow and spread. If you have a sump or you are placing the filtration media on the base of your aquarium, you can still do this. Just make sure the flow in your aquarium is off and the water is still. Affording the bacteria time to settle.

We then leave the bacteria to coat the surface of the filtration media for around half an hour. When that has passed, we can turn everything back on. The bacteria should have established itself on the surface of the filtration media and should be ready to start processing the ammonia that passes over it.

Now it is just a waiting game. Test each and every day for ammonia. When the ammonia levels drop to zero, you can begin cycling your aquarium as usual.

In Short

A lack of surface area for nitrifying bacteria to inhabit can cause an apparent slowing down, or stalling, of your marine aquarium’s cycle. This is far more likely in aquariums that don’t have rocks or sand. We can fix this using highly porous filtration media that we add to our hang on back filter, canister filter, sump, or directly to our aquarium. Seeding the media with bacteria using a bottle of nitrifying bacteria. We then, simply, wait for our cycle to resume. Thanks for reading and spending your time at Simple Reefs.