Filtration and Flow Rate

There is lot of misinformation out there in regards to filtration. 80% of people having aquarium in their home, have insufficient filtration system installed on their tank.

Filtration go hand in hand with flow rate, most people don't realized how important the flow rate are. 80% of people that have insufficient filtration system also have insufficient flow rate, this is often the root cause of the problem hobbyist are face today.

Many different type of filter sold on the market today, the most common are HOB or HOT (hang on the back/top) type filter, wet/dry filter, canister filter and reef type sump filter.

HOB filter are small compact inexpensive filter, very easy to operate. These filter use replaceable cartridge filled activated carbon, some brand also include a bio sponge. The cartridge need to be replace on a monthly basis. They are good for small tank from 5 to 20 gallon in size, because of their small size, it has a very limited surface area for bacteria to grow, therefore, you are limited to just a few fish per tank.

Wet/dry filter has been around for a long time, it is the most popular filter in use today. Wet/dry was originally develop for the wine industry, at some point the past, someone decide to adopted for aquarium use, and soon everyone start to using it.

A wet/dry filter is basically a tank with chamber setting below the main display tank, the chamber filled with plastic bio ball. The water is drain to the chamber by gravity, pass through the bio ball then pump back to the main tank via return pump, simple and easy to use. The bio ball in the chamber provides surface area for the bacteria to grow, its large size chamber does has more space then the HOB type filter, however, it does not reduce nitrate.

Canister filter is enclosed filter with multi chamber or tray can be packed with different type of filter media like carbon, bio ring, sponge etc. Its an all in one type of filter with biological, mechanical and chemical filtration in to one unit.

Reef type sump filter, very similar to wet/dry filter. A tank with divider sets below the main tank. Water drain by gravity in to the a mash bag called the sock, the sock catch's all the large debris, the water then pass through a chamber filled with either live rock or live sand, mud or both, a third chamber may have some macro or micro algae grow in it. The water is then pump back to the main tank via return pump.

So far, we have quick look on the different type of filters available in the market place. Now lets take a look at flow rate.

What is a flow rate? Flow rate is how many times the water pass through the filter in a hour.

Example: you have a 20 gallon tank, you use a HOB filter that pump about 100 gallon an hour. This means you are turning over 50% of your total water volume an hour. Is this enough? Unfortunately, no! At 50% you are only running 100 gallon an hour, the optimal flow rate for any aquarium is 10 times an hour - fresh, salt, pond all the same.

A 50% turn over ratio is too slow, not everything get taken out by the filter. Too fast of flow rate, not enough resident time for the filter and bacteria to process the waste. What you need is an optimal flow rate and that number is 10.

Everything you ever read in the past said differently, 5 times for fresh water, 10-15 for salt water some even suggest 20 times the flow rate for salt water. This is what the majority of people are running right now, and the same people are having some kind of problems day in and day out. How many times have you hear people say:

I can't keep more then 4 or 5 fish in my tank?

I just can't keep anything alive for long?

My nitrate or ammonia are high. Salt water are too difficult to do.

I like to keep discus but they are too hard to keep.

If you take a close look of their problem you will soon discovered the root cause of their problem can usually be trace back to one of the following: insufficient filtration: either too fast or too slow, too much fish or livestock and over feeding.

How much filtration and how many filter do I really need?

The filtration you need depend on your flow rate and that in turn depend on the size of your aquarium.

Example: A 20 gallon aquarium require 200 gallon an hour of flow rate, you'll need a filter that meets this requirement - 200 GPH. So, if your HOB can only do 100 GPH then you will need two of them of same brand and model or get a larger HOB filter with a more powerful pump.

The problem is most pump sold today either by itself or included with the filter are over rated on the flow rate. Lets say you see a filter on your local fish store (LFS), on the box it says is rated for aquarium up to 100 U.S. Gallon. You happened to have a 100 gallon aquarium that need a filter, so you buy this filter and think to yourself that all I need. Boy, you couldn't be more wrong.

A 100 gallon tank need 1000 GPH flow rate, 10 times. The filter you just purchased has an flow rate of 350 GPH, so off the back you are way way below the requirement. Remember I said before manufacture often over rate their filter and pumps, you take 350 GPH divide by 1/2 you'll get 175 GPH, that would be the flow rate of this filter. Don't believe me, take a gallon container and measure how long it take to fill a gallon of water from your filter, times 60 seconds you'll gallon per minute. Then times 60 again you'll get gallon per hour. Compare the number to what is publish from the filter manufacture you'll see the actual flow rate is about 175-220 around 1/2 or little bit more then what manufacture's claim.

Now that you've establish the flow rate of your newly purchased filter, can you honestly said this filter can adequately filter a 100 gallon tank? Even if the filter is pumping at 350 GPH you'll still need minimum 3 of the same filters to adequately filter a 100 gallon tank. Somebody will point out 350x3 = 1050, is too fast. No is not! Remember all filter will clog sooner or later, as the filter begin to clog, the water flow will decrease so as your flow rate. You always want to go higher then the required flow rate not under. If is too fast you can turn it down, but if you go under, there is no way to dial it up other than change pump or filter.

Most aquarium setup are under filtration from the beginning, as more live stock are added to the tank and more wastes are release in to the aquarium water, the water quality start to drop rapidly. First, ammonia set in, the number 1 fish killer, then nitrate start to accumulate. With water quality going south, other problems starts to pop up. Fish getting sick and dying, things going down hill from this point, soon you lost most or all of your fish. You are sad and upset but you don't really know why your tank has just crash. You go to your LFS, you told them what had just happened, you explained your setup, how many LFS you think will tell you that you are under filtration? Not very many.

Now that you understand the importance of having enough filter and flow rate, let's go back to the Hiatt filtration system, I'll show you why the Hiatt system are superior then other filter system.

The Hiatt Filtration System

With the Hiatt system the first thing we do is to find out the size of tank in gallon. Once we know the how many gallon of water need to be filter we then use a simple formula to determent how much pound of Tri-Base carbon is needed, that in turn tells us what size of filer and how many are required. It also give us the flow rate, which we can use it to find the right pump. Here is the formula to calculate how much pound of Tri-Base carbon is needed.

Total Volume of water X .1667 = Pound of Tri-Base carbon

Example: 20 gallon tank will require 3.3 lb. of Tri-Base carbon, and a 200 GPH flow rate. A 60 gallon tank will require 10 lb. of carbon and flow rate of 600 GPH.

What this mean is a 4 stage canister filter with a 200-350 GPH will do the job. It has enough volume to hold 3.3 lb. of Tri-Base carbon and with a sufficient flow rate for a 20 gallon tank. In a 60 gallon you will need multiple canister filters, because a 4 stages canister filter can only hold about 4 lb. of Tri-Base carbon. In order to have the required amount of Tri-Base carbon, you are going to need 3 canister filters, which will give a combine flow rate of 660-1050 GPH. Because the flow rate are often incorrect, you are still fall within the requirement.

After the filter is up and running, you acclimate couple of Percula clowns to your new tank. The Right Now bacteria is added to the tank and the two clowns are introduce to the new tank, to start the cycling process. Immediately the Right Now bacteria will start breaking down and eat protein, ammonia, nitrite, Nitrate, and phosphates. After 24 hours, your new tank is now cycled and you didn't lose any fish. 48 hours later you can add two more fish and continue to add fish every few days until you have enough fish. With the traditional filter is 1 inch of fish per every 5 gallon of salt water. With the Hiatt system is 1 inch of fish per every 1.25 gallon of salt water. You can achieve much higher bio density with the Hiatt system because you have a fully establish bacteria bed from day one, where normally would have take you anywhere from months to may be years to establish.

That's all you need in the Hiatt System: a canister filter filled with required amount of Tri-Base carbon, pH Rock, Right Now Bacteria and the correct flow rate and drain. Simple to setup and maintain, no expensive skimmer, UV, calcium reactor and other unnecessary item to run and care for.

As for the canister filter we recommended the Red Torpedo Filter when using the Hiatt system. The reason we choose the Red Torpedo filter is because its capacity to hold large amount of Tri-Base carbon and pH rock in a single filter vs. the regular canister sold today. The smallest Red Torpedo can hold up to 12lb. of Tri-Base carbon or 34lb. of pH Rock, that's enough filtering martial to filter a 75 gallon salt water aquarium and each Red Torpedo can hold pressure up to 175 PSI. This pressure is very important, is cause the water to push through the filtering media instead of flow around like in an unpressurized wet/dry system.

Of course, you don't have to use the Red Torpedo filter if you don't want to. If you can find other filter with a large chamber to hold the required amount of Tri-Base carbon and pH rock you can use that.

Flow Rate in a Reef tank using the Hiatt system

Now lets take a look flow rate in a reef tank. Everything you've read so far is based on if you have a fish only tank or mixed tank with lots of fish. A lots of so called "experts" believe reef tank required different flow rate all together. I don't know where did those "experts" get the ideas from since in the ocean fish and coral are living in the same environment and are subject to the same flow.

Here is what we recommend for reef tank:

1/3 of required carbon and 10 times the flow rate. Example: 60 gallon need 10lb. of TBPC and 600 GPH flow rate, for reef you will need just 3.33 lb. of TBPC and 600 GHP flow rate. The reason is coral doesn't produce much wastes and coral does need some nutrient in the water. If you have a full amount of carbon in a reef tank, the bacteria will strip the water clean with all of its nutrient, some of your coral may not do well in such low nutrient environment.

Remember, every tank is different if you are not sure how much carbon you need, please email or give us a call first. We want you to be successful the first time, not to make any mistake that require you to fix later.