Filter Floss: When to Replace It for Optimal Aquarium Health

A common question among new aquarium owners is, “How often should I replace my filter floss?”

And one of the most common answers you’ll see on popular reef keeping forums is “every 2 to 3 days”.

There are two slight problems with this rote piece of advice though:

  1. It could cost you extra money. And,
  2. It could starve your tank.

Every tank is unique, including yours. Just because changing the filter floss every 3 days works best on another person’s tank doesn’t mean it will work best for yours.

How often you change your filter floss will depend on your bio-load and the maturity of your tank.

filter floss cut into strips
Filter floss cut into 1 inch strips for placement between sump baffles.

Consider a new tank that is less than three months old…

Changing the filter floss too often could deprive the bacteria and other microscopic critters of the food they need to develop. This may result in your tank taking longer to mature than usual.

Likewise, changing filter floss too often in a established, mature tank could strip the water of too many nutrients causing the coral to starve.

So where does the common ‘2 to 3 days’ come into play?

As a starting point.

Filter floss isn’t needed until you reach your desired nutrient levels. Phosphate of 0.03 ppm and nitrate of 1 to 5 ppm are most typical.

Once your tank is at your desired nutrient levels begin using filter floss.

For the next 4 to 6 weeks replace it every three days.

Be sure to test your phosphates and nitrates at least twice a week during this period.


Let Your Tank ‘Tell’ You When to Change the Filter Floss

If your nutrients continue to rise during the test period switch to replacing it every 2 days – and consider adding additional filtration such as a skimmer and/or granular activated carbon if you don’t already use them.

If your nutrients hold steady or drop closer to zero during the test period, try replacing the filter floss every five days.

Keep testing for 4 to 6 weeks.

If the nutrients continue to hold stable or drop, bump the replacement schedule out to once a week.

Keep testing. And keep bumping the schedule out.

When your nutrients start to rise a little, stop and switch back to the previous schedule. Congratulations! You’ve found your filter floss replacement ‘sweet spot’.

For example, if they were stable when you replaced the floss every 7 days (once a week) but started to rise when you replaced it every 9 days, stop. 7 days is your replacement ‘sweet spot’.

Changing it more often than 7 days would just be wasting money. And waiting longer than 7 days will cause your nutrient levels to rise.

What if your able to go for several weeks without replacing the floss and still see no rise in your nutrient levels?

Well then you may not need to use filter floss at all. It would indicate the other biological and/or mechanical filtration in your system is more than enough to keep your nutrient levels in check.


Dosing Phytoplankton: Is It Good for Your Aquarium?

Dosing phytoplankton can provide many benefits for some aquariums, and yet may cause problems for others.

Determining whether or not it’s a good idea to use it can often be difficult.

And a quick look on popular saltwater aquarium forums reveals quite a raging debate.

Some folks argue phytoplankton is the foundation of the food chain in our oceans, and is therefore beneficial to life in a reef tank.

Others say it can’t be directly consumed by coral or most other aquarium inhabitants … and therefore does nothing except to add unneeded nutrients to the water.

I’ve tried dosing phytoplankton in my 24-gallon mixed reef aquarium on two different occasions. Each spanned one month.

The only change I noticed the first time was an decrease in the time it took for film algae to grow on the glass. Before dosing phytoplankton I had to clean my glass once every 4 days.

After I began dosing phyto, I had to clean it every 3 days.

Bottle of Phytoplankton

There were no changes in coral growth or color. And no other noticeable changes, so I stopped dosing it.

Over-filtration¬† in the months that followed caused my water to become a bit too ‘clean’. I noticed slower growth and paler color in some of my corals. So, instead of running a skimmer and filter floss together, I decided to use just the skimmer.

After a couple of months my nutrients were still measuring in a nice, low acceptable range: 0.01 phosphates and less than 3 ppm of nitrate.

But there was still just enough of an increase in each for my corals to regain their vibrancy and grow a bit quicker. They were consuming the extra nutrients before they could cause my measured values to rise.

Now, you’re probably wondering, “what does this have to do with dosing phytoplankton?”

Well, I also noticed another unexpected surprise. New sponges began to grow on my live rock.

When I first set up my tank, I used live rock from Tampa Bay Saltwater. It was COVERED in barnacles, sponges, and other life.

Unfortunately, as my tank matured, and my nutrient levels came down into proper ranges, they slowly died off and faded away.

When I saw these new sponges starting to appear, I thought dosing phytoplankton might help them to spread even more.

So tried dosing phyto for a second time.

The result?

The same as the first time. I’ve had to clean film algae off my glass twice as often. But I’ve noticed no difference in the growth rate of the sponges or anything else.

So I’ve stopped dosing it. And I doubt I’ll try it again.

It is apparent to me now that my tank does not have enough phytoplankton-dependent life in it any more to make it worthwhile. The nutrients from uneaten fish food, fish poop combined with twice-weekly feeding of coral food is enough to keep my tank happy.

However, I do wish I had known about dosing phytoplankton when I had first set up my tank with that live rock.

All those original barnacles, sponges, porcelain crabs, and the myriad of other filter feeders would probably still be alive and thriving if I had started dosing phyto then.

That is perhaps the biggest key to knowing if it’s worth dosing phytoplankton in your tank.

If you have a lot of filter-feeding critters in your tank, it is definitely worth giving it a try.

On the other hand, if you only have a few, or none, then dosing phyto probably isn’t worth it. You will only be wasting money and adding unnecessary nutrients to your tank.


Stylocoeniella coral: a unique SPS for any aquarium

Stylocoeniella is a colorful and captivating  SPS coral that can bring drama and beauty to most any aquarium.

This encrusting coral is often described as a cross between montipora and psammacora.

It’s a fairly hardy SPS coral that does best in low to medium lighting and medium to high flow.

Where it differs from montipora and psammacora is in its polyps. They are a bit longer and often extend 3-4 mm beyond the base. This allows the polyps to move around in the flow a little. It’s a bit like watching ripples move across the top of a pond.

It does best when place in the lower half of the tank.

And it comes in a dazzling array of colors. Some of the most common are green, red, and orange.

Now that it is beginning to catch the eye of collectors and coral breeders, more vibrant variations are available as well. Colors such as purple, pink, blue, and rainbow are now available.

Electric-blue stylocoeniella
Electric-blue stylocoeniella (center).

Designer variations are also starting to appear as well. Examples include Burning Bananas, Sunset, and Looney Tunes from Jason Fox.

Feeding is straightforward and no different than most other SPS. Most any SPS food will be accepted, such as Coral Frenzy and Reef Roids.

And their ability to grow in lower light makes them a great coral for adding life and color to shaded areas of rock work.

If you’re looking for an SPS coral that is unique yet easy to care for then look no further.

Stylocoeniella is colorful.

It adds a sense of drama and motion to your aquarium.

Unlike most beginner corals, it is still rare and different enough to be an eye-catcher and topic of conversation.

And it requires very little, if any, hand-holding or special care.

Put simply, it’s a rare, eye-catching gem than can be treasured and appreciated by novice and seasoned reef keepers alike.