Guide to cycle a Saltwater Aquarium

Saltwater Aquarium or Freshwater Aquarium, The Fish, Corals, ecosystems, Parts DIY and so on
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CAROLINE D.C. JOSE
Posts: 26
Joined: Fri May 03, 2019 9:16 am

Guide to cycle a Saltwater Aquarium

Wed Oct 14, 2020 4:32 pm

Cycling your saltwater aquarium is a critical process. All aquarium must endure before they are ready to be populated with fish and corals.

So what is cycling you ask? The term refers to the Nitrogen cycle, a process where beneficial bacteria start building up in your aquarium breaking down harmful ammonia (NH3), into nitrite (NO2) and then nitrate (NO3).

When you first set up a brand spanking new aquarium, your aquarium tank and equipment will be squeaky clean. Be prepared to say goodbye to this new aquarium smell, because things are about to dirty, but trust us, dirty is a good thing at this point.

Cycling your aquarium can take anywhere from 2-6 weeks, depending on your setup, and how proactive you are in helping the process along the way. Patience is a virtue in the aquarium hobby, and if you’re already groaning at the possibility of an empty glass box in your living room for a month, well, you might want to reconsider your decision to get an aquarium, because, in this hobby, good things come to those who wait.

Get Started With Live Rock
To start the cycling process you need to seed your tank with rocks, or filter medium that already contain a mature bacteria population. The best way to do this is with a big piece of live rock, or a bag of ceramic filter medium that’s been hanging out in a mature tank for at least six months. You can get live rock from your local fish store, or from a friend with an established tank, just keep your eyes out for any pests or excessive algae growing on the rock.

Examine the undisturbed rock in the water for any pests before transferring it to your tank. You can use a soft bristle brush to scrub off any algae, but be careful there are no zoanthids or palythoa polyps hiding on the rock. Scrubbing a rock with these polyps can be deadly to your health.

Once your tank is up an running and you’ve added some mature liverock, the bacteria on this rock will need a source of ammonia, so they can start doing their job, and colonize your tank. Fish waste, and decaying organic mater like fish food, is a common source of ammonia, although it is not recommended to start adding fish before your cycle is complete. Fish can quickly produce more ammonia than your new tank can handle, and a sudden ammonia spike can spell disaster for your animals.

Instead let your tank run with a live rock for a week or more and then add in a couple invertebrates, like hermit crabs, crabs, and shrimp. This bunch of critters is also called the clean up crew. Feed your invertebrates a very small pinch of food each day and the waste they produce will create ammonia.

Test Test Test
During the cycle process, you want to start testing your aquarium almost every day for ammonia, nitrites and nitrates. This will help you understand if the cycle is underway and when it is safe to start adding livestock.

After a week or ten days, you should see a spike in ammonia concentration, jumping from zero to a higher number. This is followed by a spike in nitrite, follow by a spike in nitrate. After your nitrate goes up, your nitrite and ammonia level should fall back down to zero. Once you have observed this change in water chemistry your Nitrogen cycle is complete.

What Going On
The cycle starts with ammonia, but the goal is to establish a colony of nitrobacter bacteria which process nitrite into less harmful nitrate.

How it works is nitrosoma bacteria start converting ammonia, to nitrite. Then nitrobacter bacteria being consuming the harmful nitrite into less harmful nitrate.

Nitrate levels should be in trace amounts in the aquarium, and a safe range for a reef tank is below 5ppm. If you have a fish only reef tank you can have your levels higher up to 40ppm, however, it is always recommended to have level lower than 5ppm. That being said, certain soft corals and especially giant clams appreciate a little extra nitrate in the water, and there are plenty of successful reef tanks, even SPS dominated, which succeed in water with nitrate concentrations upwards of 50ppm.

Once nitrobacter are growing they need oxygen and food to survive and thrive this is why they are called ‘aerobic’ bacteria and grow especially well in wet-dry filters. The nitrobacter will start growing on all the surfaces of your tank including the walls and rocks. When you are testing your water and start to see nitrate level creeping up you know nitrobacter is getting things done.

During the cycling process, you need to go through all three steps, ammonia spike, nitrite spike, and nitrate accumulation. If for some reason you decide to clean your tank or do a water change after seeing a spike in ammonia, you’re going straight back to square one and will have to start the process all other again.

To monitor your ammonia level, you can purchase ammonia alert tags by Seachem which stick to the inside of your aquarium glass. This will give you a quick and easy way to monitor ammonia levels.

The older your tank gets the more nitrobracter bacteria are maturing, reproducing and colonizing your aquarium, esentially speeding up the cycling process. However, just because you’ve completed the cycle dosn’t mean these processes arn’t still continuing. Every time you add a new fish, or have food left over to rot in the tank ammonia levels start to rise.

Once your cycle in complete, and you see nitrate levels rise, and ammonia and nitrate level fall, you are safe to add your first fishy friend. But, remember what I said in the beginning about patience… You always want to take things slow, adding fish one at a time and letting your tank adjust.

Now that we’ve driven home the point of taking things easy, slow and steady, we want to let you in on a little secret. The nitrogen cycle is a necessary step for starting all saltwater aquariums, and aquarium manufacturers want to make this process as quick and painless as possible.

There are a few products on the market which help kick-start your biological cycle with a dose of nitrifying bacteria. One of our favorites is BioDigest by Prodibio, which are vials of lab-grown bacteria to start of your biological cycle.

BioDigest is a concentrated bacteria for all steps of the process. Each vial lasts about 15 days in the aquarium and if you are looking to speed up the process you can add a new vial every 15 days, instead of trying to increase the dose with two vials from the get go.

A Dose Of Nitrifying Bacteria
Another product to start you bacteria cycle is FritzZyme 9 which contain a balance of live nitrifying bacteria to seed your tank. This product can be added to new tanks or for a boost of bacteria to established systems, especially after large water changes.

And if you really need to get a tank going in a hurry, Fritz also offers a FritzZyme TurboStart 900. This could come in handy if you are setting up a quarantine tank, or for frag, vendors setting up tanks for the weekend.

Dr.Tim one and only live nitrifying Bacteria for saltwater also help to cycle your tank instantly.

Get Cycling
Whatever method you use for cycling you aquarium the important part is to understand why you cycle in the first place. Cycling you tank ensures good bacteria builds up, and is able to consume ammonia before it gets out of hand.

Both ammonia and nitrite can be deadly to fish, even if small doses, so it’s essential to control, even nitrate can be a problem if left unattended. If you’re just starting out we recommend the slow and steady method. This gives you time to learn how to test and track your water quality, and make sure your tank is running smoothly before you go adding livestock.


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Maylene Arceo
Posts: 14
Joined: Thu Apr 16, 2020 10:48 pm

Re: Guide to cycle a Saltwater Aquarium

Wed Oct 14, 2020 4:50 pm

1. Fishless Cycling Takes Longer - For some reason people think fishless cycling only takes a few days. Wrong. Fishless cycling takes longer than cycling with fish. Fishless cycling takes 10 to 14 days because you, the aquarist, are adding a lot of ammonia. Cycling with fish where you add a FEW fish and the bacteria generally takes 4-5 days but this is at a lot lower level of ammonia. There is no wrong way to cycle just have a little patience.

2. Live Sand - if you are going to use live sand chances are high that cycling with take a little longer. Live sand contains organics and bacteria that breakdown those organics into ammonia. This causes two issues - high ammonia which slows the process and a bacteria bloom. Those bacteria take micro-nutrients out of the water which the nitrifiers need when fishless cycling. Follow the set-up guide for the tank and get everything running. After 24 hours measure the ammonia BEFORE adding the ammonium drops. If your water has ammonia then do not add the ammonia drops at this stage. Wait until ammonia disappears before adding more.

3. Bare-Bottom or lack of biomedia – Bare-bottom tanks take longer to cycle because the bacteria need a lot of surface to stick too. Bare-bottom tanks lack surface area. The glass (or plastic) bottom of the aquarium is not a good surface. This is especially true in quarantine systems - there is not enough good surface area for the bacteria. Many types of sponges are not great, either. Plus with lots of water circulation the bacteria are swept into the mechanical filter and when it is cleaned they are tossed-out. One solution, if you really want the look of a bare-bottom tank, is to add a layer of glass beads or marbles to the bottom. Cycle the tank and then slowly start to remove the marbles over a week or two AFTER cycling.

4. Space Age media - Along with #3, people will use an artificial media made from glass, ceramic or some other space age media. While these can work eventually the bacteria don’t seem to colonize them very fast. So just putting a few blocks in an otherwise bare-bottom tank will not work well. Also remember long-term these types of media need to be kept clean so water can freely flow through them.

5. The Water Needs to be Chlorine/Chloramine Free - Most tap water contains chloramines or chlorine to kill bacteria and make the water safe to drink. These chemicals need to be neutralized before adding the One & Only Live Nitrifying Bacteria. Use our First Defense to detoxify your water.

6. High Ammonia - People think they have to feed the bacteria every day or the bacteria will starve. Bacteria are not human; they do not need to eat every day to survive. Because the ammonia-oxidizing bacteria work faster than the nitrite-oxidizing bacteria the ammonia will read zero sooner than the nitrite will read zero. Don’t believe the internet that says the bacteria will starve if there is no ammonia. Follow the recipe directions - 1) do not add ammonia if either ammonia or nitrite is above 5 mg/L-N and 2) only add a maximum of 4 drops per gallon do not continue to add ammonia until you get a reading of 2 ppm or else you risk overdosing the system with ammonia.

7. Overdosing with Ammonia-Removing Chemicals - It makes little sense to add an ammonia removing chemical to your aquarium water when you are then going to add ammonium chloride drops. So don’t! Just use a ‘simple’ dechlorinating agent like our First Defense to remove any chloramines or chlorine. Some popular brands of ammonia-removers advertise that they do not affect the nitrifying bacteria even at high doses - this is wrong. The overuse of ammonia removing chemicals will stall the cycle.

8. High Nitrite - Related to #6. Many times the bacteria can quickly handle the overdosing of ammonia and you will get a zero (0) ammonia reading but the nitrite just gets higher and higher. High nitrite is very common when you rush the process or add too much ammonia too quickly. High nitrite inhibits the bacteria and stalls the cycle. If you have super high nitrite do a 33-50% water change without disturbing the substrate. Do not add chemicals to de-toxify the nitrite.

9. No Nitrite - The opposite of #8. The bacteria work so well that there is no nitrite and so you assume the bacteria are dead. If your water is ammonia and nitrite-free add another dose of ammonia. The goal of adding Dr. Tim One and Only is to add enough bacteria to remove the ammonia and nitrite quickly and in many cases you may not see either while cycling.

10. No Nitrate - The end product of nitrification is nitrate. So logically you should be able to measure nitrate to make sure your aquarium is cycled – this is correct. The issue is that the majority of nitrate tests do not measure low nitrate values very well. Until the nitrate get around 20 mg/L the kits may not register a reading.

11. Low pH/ Soft Water - the nitrifying bacteria do not work fast at low pH values (under 7). They also don’t work fast in RO/DI water or naturally soft water. It may seem to make sense that pure water is the best - it’s pure! But that is not true. The bacteria need water with minerals and they prefer water with a higher pH value (7.6-8.3).

12. Specialized Tanks - plant tanks, shrimp tanks etc. with specialized soils that leach ammonia or keep the pH low or add lots of tannins to the water all negatively affect the performance of the bacteria. That means cycling will take longer. You either need to be patient or add a lot more nitrifying bacteria to the system.

*Dosing Dr. Tim / Fishless or with Fish Cycling. Though this Above information is for Dr. Tim, this guide also can help you to understand how to cycle your tank.

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