Active Sponge Filter

Filter - Active Sponge Filter

Regular price $11.95
Shipping calculated at checkout.

You should choose a carrier that can get these to you within 2-3 days transit time, Priority Mail is a very unreliable choice when selecting the shipping method. Please do NOT order so it travels over a weekend. UPS does NOT deliver on weekends. 

NOTE: If you test your water after adding the filter and have no ammonia and no nitrites, then everything is good. You do NOT need to see nitrates to know it's working. 

Made from our Pro-Level Reticulated Foam, specifically suited for colonizing nitrifying bacteria at the highest levels in aquariums.

Size: Actual filter size varies with each filter.

  • Large - range from about 50-100 cu/in.
  • Small - ranges from about 30-60 cu/in.  

We cannot tell you how many you need for your tank. Tank size does not determine how much filtration you need. Bio-load is the determining factor and it's a complex formula. In general, you have to use your experience to know how much filter material volume your situation needs. If you are inexperienced and must guess, then go with 1 filter per 20 gallons, knowing that it may be over or under-filtered. If you are going to use the active filter solely to establish an existing filter, then one or two max, would be enough for almost any size tank.

If you are putting the filter in with newborn fry or a tank that is 5 gallons or less, then the 50ppi (pores per inch) is the best choice, otherwise, the 15/30ppi filters are a better deal for a much larger size. The Large can be either 15ppi Blue or 30ppi Black - our choice. We send what is ready. The Small is 50ppi Charcoal. 

It comes with a lift tube. You must supply the airline.

We ship when you order, so it's your responsibility to avoid weekend and holiday delays. You should try to make sure the carrier you choose will get them from our location (14760) to yours, within 2-3 days. They will survive longer, but it will also take longer for the bacteria to build back up to the levels needed for your tank.  Orders that arrive after 8 AM est, will not ship until the following business day.

When you receive these, make sure to add any water in the bag to the tank. Do not worry about it being dirty. It is full of nitrifying bacteria and you do not want to throw this out or siphon it out with a water change until the aquarium is fully established.

Filter Setup

When receiving the filter: Be sure to add the dirty water in the bag to the tank with the filter. It contains valuable nitrifying bacteria. 

Setting Up Filter: Run an airline to the lift tube. Insert the airline into the hole in the top side of the lift tube and thread it to within 1/2" of the bottom. Then insert the bottom of the lift tube into the hole in the sponge. You can put the filter into any part of the aquarium. If it floats, gently squeeze the air out of it.

Some people cut these to fit inside of power filters. That will work if the fit is tight, but if water can travel around the filter instead of through it, then that is what the water will do and it will not be as effective in establishing your aquarium.

We are not fans of "fish-less" cycling. It seems most times a customer is having trouble cycling their aquariums with our filters, it's a "fish-less" cycle. It's possible some additive in the ammonia they're adding, is interfering with their water test kit readings or is simply doing something to the nitrifying bacteria. Either way, if you add one of our active biofilters, your tank is ready for fish. Forget about adding ammonia first. Also, do not use ammonia removers when conditioning the water - only chlorine removers should be used if you have chlorine. Ammonia is essential for the bacteria in the filter to survive and grow. If the ammonia gets dangerously high (fish are struggling at the surface), then a water change is the best option.

Occasionally someone complains that their nitrates didn't go down after using this filter. It's important to know that only ammonia and nitrites are lowered by biological filters. Nitrate will actually go up, which is why water changes are still necessary no matter how good the filtration is.  

How They Work

These filters are fully "cycled", containing all the many species of nitrifying bacteria a fully established aquarium needs. Once put into a tank, the tank becomes instantly cycled. "Cycled" aquariums can still get ammonia or nitrite readings from a test kit. Cycled means you have the proper number of nitrifying bacteria species and the proper proportion of them. However, the population may not be high enough to handle all the waste produced by your animals. Assuming you have enough filtration for your bio-load, and the water conditions are good for bacteria growth, the bacteria will double in population approximately every 24 hrs in until it reaches the level where it can handle the waste in your tank. That can take anywhere from minutes to days, depending on the bio-load in your tank. Do not use ammonia neutralizers, only chlorine removers unless you have chloramines.  It's best to not do water changes for the first week unless you see the fish struggling at the surface for oxygen. If you must do a water change, we recommend this to remove chlorine.

All of our tanks contain snails, so these filter may have small snails and/or their eggs on them. The filters also have other small micro-life typically found in many aquariums.  There are paramecium and rotifers, There might even be flatworms or bristleworms. These are NOT parasites, but small aquatic animals that clean up extra food and fish waste. We never see them in our tanks and we look for signs of them often. We don't overfeed and they are most visible in tanks that are overfed.  If you don't like them, they are easily killed with formalin.  Just treat in a 5-gal bucket for a couple of hours and then add the filter to the tank. The filters also contain the decomposed waste generated by the plants and animals in our tanks. They will be "dirty". This is not harmful and is what happens in biological filters. The nitrifying bacteria are short-lived and create a large amount of bio-floc as it dies off.  All of this is normal, but if you are offended by this, please do not order. Filters that are too clean, can be a reason for having a difficult time establishing a bio-filter since cleaning a filter too much harms the bacteria.

There are likely hundreds of species of nitrifying bacteria in a tank that has been "established" for over a year. This is why those commercial "starter" products with a few species, don't work very well.  Our filters contain all the species in balance and is why they work so much better.

The bacteria survive shipping quite well, but faster is better when deciding on the shipping method during checkout.  If the filter freezes, the bacteria may be killed so pay attention to the weather, here and where you are.  Try to avoid having the package sitting outside after delivery.  It can be risky to order when night-time temps are much below 0 F. We are in a potentially very cold area of the country (zip 14760).  Heat does not bother the bacteria.  In transit, the bacteria go into a dormant state and reactivates in the presence of ammonia and nitrites.  A percentage of them will survive for quite a long time out of an aquarium, so even with delays and bad weather, they persist and will often still work, though a bit slower as they recover.

The filters vary in size and shape within the range listed.  All of our Active filters are the "Internal Weight" filter version.  We have too many filter types to have them all in an "active" version and this type is easy to ship without water leaking from the bag.

These filters are "established" in our disease-free aquariums.  This assures that no pathogens are transferred to your fish.  This is safer than using a filter out of your own tanks, since few, if any are disease-free.  These filters have been running for about a month in our super healthy tanks to ensure the nitrifying bacteria are well established within the sponge.

Customer Reviews

Based on 209 reviews
Rachelle Gaon
20g tank cycled in 24 hours!!!

I bought 2 large of these active sponges for my 20 gallon tank because I've been struggling for sooooo long to cycle my tank. I wish I've known these earlier. My ammonia was at 4ppm, 0 nitrites, 20 nitrates. Now I got these, 24hrs later, I have 0 ammonia, 0 nitrites, 40-80 nitrates! Thank you so much for this product!

Caitlin Padilla
Rough newbie start but still cut down cycle time

Received my filter on 9/29 and immediately placed it in my tank. I chose not to set it up with an air pump, but instead cut some of the sponge up and placed it in my canister filter, squeezed the majority of the bacteria out into the tank, and left the sponge in the tank. Doing this again, I probably would have set up the two filters to run together for a few weeks until my main one was established, it would have made my life easier and I have no doubt my tank would have been cycled within a day or two.

Once I had the sponge in, I tried a fishless cycle using the ghost feeding method and quickly realized I was wasting my time, and I needed to try something else. I purchased Dr Tim's Ammonium chloride and have been feeding my bacteria friends with that. It's been a week since I've been feeding them this way and I have close to 0 ammonia consistently after I drop more Dr Tim's, 5 nitrite, and 5 nitrate. With some more time and a few water changes to remove some of the nitrifying bacteria, I'm confident the nitrite levels will drop and my cycle will be completed.

Cody Luera
Shipped to Arizona and worked!

I had tried to do a fishless cycle for three weeks, using Dr. Tim's Ammonia and Frtiz Zyme 7 bacteria. I was testing using an API master kit. After three weeks, I still hadn't cycled. It seemed my cycle was stalled with a nitrite spike. This could've been my fault. It seems fishless cycling is hard for beginners.

I discovered the Angel's Plus Active Filter when I was looking at fish forums. I gave it a shot - they are in New York, and I shipped with UPS Ground to Arizona (September, so still really hot in AZ). I placed an order on Wednesday. As promised, the filter arrived by Saturday. I set it up in my aquarium, along with the dirty water in the bag. In my case, it took about 4 days to cycle. I added fish on day 2, and by day 4 I had zero ammonia and nitrites, and had 5 ppm nitrates.

Highly recommend this filter. Made it stupid easy to ensure a safe environment for my fish. I would definitely use their filter again.

Karen Stauffer
Good Cycle Kick-Start

I was pleased with the seeded filter. Price was great, shipped out quickly and my tank finally jumped into the second and now final stage of cycling. I wished I had bought this from the beginning of my process instead of waiting for 3 months to try to let the cycle happen naturally. I plan to keep the filter in my tank as a back-up in case I ever need to kick-start another tank or in case I ever have a cycle crash for any reason. Very pleased. Thank you for offering these!

Steve Young

Cycled our tank for our axolotl in days.