Weapons of Nutrient Destruction: cone and pellets with sugar on top

I have recently added two new components to my nutrient export methods, a cone shaped skimmer and a new filtration media called Biopellets. I also continue to use my old and proven CaCO3 slurry filtration and DOC (dissolved organic carbon) dosing. I’ve also experimented with another method based on microscopic clay particles. Here is a short review of these methods.

CaCO3 slurry

One of the idiots responsible for cloudy water

I started experimenting with this method when I noticed that I couldn’t keep the water clear with conventional mechanical filtration. I have four Pomacentrus simils that keep digging the sand bed and are constantly introducing small particles into the water column. I was using a traditional setup of a powerful powerhead and some filtration mat but I clearly needed something more efficient.

I had used very fine home made aragonite (CaCO3) powder over the years whenever I thought the water could use some “polishing” and it worked very well. So this time I was going to do the same but together with mechanical filtration which would trap most of the particles and thus create much more efficient filtration media. Fresh CaCO3 surface is an excellent binder of dissolved organic matter (DOM) and is also known to bind phosphate so those were an added bonus.

It quickly turned out that the enhancing mechanical filtration part of my idea was not working so great – the rate at which the fish add particles is just too fast for any filter to keep up with (unless I add the filter into the display tank itself which I certainly do not want to do). Instead I noticed much improved water clarity and  less yellow coloration. So much so that I completely removed the activated carbon (GAC) filtration I had used for years. To my surprise, daily additions of CaCO3 slurry was able to keep water very clean even without the help of GAC. I did eventually add some carbon back to filtration because my feeding experiments but still the performance of aragonite powder was surprising to me.

I think this method is something more adventurous reef aquarium owners might want to experiment with. Producing your own CaCO3 slurry is very easy and much, much less expensive than buying the same stuff in those nice little blue bottles.

1. Mix together 2:2:1 calcium chloride, sodium bicarbonate and calcium hydroxide. BE SURE TO WEAR MASK OR OTHER PROTECTION. DO NOT INHALE THE DUST.
2. Fill large container with hot water
3. Slowly add the mixture, constantly stirring the solution. This will create a lot of carbon dioxide so be careful not to add the mixture too fast or it will overflow.
4. Let it sit so that the precipitate drops to bottom
5. Carefully pour out as much water as you can and refill
6. Go back to 4. Repeat a couple of times. This rinsing is necessary to get the NaCl out of the solution

Sugar

I don’t think there’s much to say about DOC dosing that isn’t well known by all reef aquarists. Sugar (sucrose, a molecule combining glucose and fructose) is just one of the possible sources of organic carbon reef aquarists can use. It is cheap and very pure form of OC.

One thing that I’ve noticed is that DOC also benefits directly certain invertebrates that are able to feed on DOM and/or have symbiotic bacteria. As I have started to use Biopellets (described later) I’ve started to wonder if it is beneficial to continue DOC dosing even if not absolutely necessary for inorganic nutrient reduction. The question is which one is more beneficial, the production of bacterioplankton by Biopellets or the direct feeding of DOC by the symbiotic bacteria in sponges, for example. Naturally dosing of organic carbon in liquid form also has its drawbacks. For example, as the DOC is distributed evenly in the system, bacteria often grow in places you don’t want them to. For example in pipes and hoses, reducing the water flow significantly or on the glasses and other visible surfaces.

I’m currently using a solution of 400 g/l sucrose. Total daily dose is 10 ml split into 8 doses that are added by the dosing pump.

Biopellets

The amount of bacteria produced by Biopellets is simply amazing

A while ago I was reading an interesting article on coralscience.org about filter feeders that mentioned a new, interesting filtration media called Biopellets. This media is a solid form of organic carbon (POC, particulate organic carbon) on which bacteria can grow and multiply.

Using organic carbon in a solid form has many benefits and hardly any drawbacks compared to DOC dosing. First of all it provides essentially a limitless amount of carbon for bacteria to utilize. The only limiting factor is the amount of free surface area. To optimize the performance you should either use the media in a fluidizing filter or disturb the media mechanically every now and then.

Biopellets also solve the problem of bacteria growing in unwanted places by concentrating much of the production inside the filter instead of distributing the organic carbon all over the system. At the same time this can also be a negative thing because of the fact that much of the particulate matter that every captive reef produce in abundance is going to be broken down somewhere else in the system, typically in sand bed and live rock. As it has become more and more evident that much of the nutrient cycling through microbial loop in reef aquariums is limited by the amount of labile organic carbon it seems to me that these processes could benefit from the addition of a carbon source (DOC). One interesting possibility is to add some pellets inside the sand bed. There is a concern about the possible H2S production but it should be remembered that there is a very oxygen rich layer on top of the sand bed that should easily oxidize H2S if it indeed was produced.

Third benefit is convenience. It is much easier to add some pellets every 6 months than it is to dose minute amounts of DOC varieties. Disturbing the pellets inside a media bag is also not a big commitment. Even I can manage to do that.

Tunicates love to eat bacteria produced by Biopellets

To me one of the best features of Biopellets is its ability to produce a huge amount of bacterial biomass which in turn is excellent food for many filter feeders. The bacteria will come off the Biopellets as large aggregates that will be broken down to progressively smaller clumps of bacteria by the pumps. Bacteria aggregates are the most important food source for many difficult to keep invertebrates like bivalves and tunicates. These animals are typically unable to filter out single bacteria (they are called crude filterers) but when they are clumped together like in nature they are filtered out extremely effectively. Fine filterers like sponges and some polychaetes are also able to eat these particles in addition to single bacteria cells. Any bacteria left uneaten will be removed by protein skimmer or they will populate other aquarium surfaces and continue their work there.

All in all I’m very impressed by this new method of providing more natural environment for reef creatures. I’m especially thankful that there still exists people and companies who are able to innovate instead of copying. Why is it that many times it is the individuals or small companies like Reef Interests that come up with new exiting ideas? Most of the larger aquarium companies seem to only copy the same 30 additives and equipment that everyone else is producing. It is then left at marketing to try to differentiate the products from the rest and everyone knows what the marketing department produces. There are many companies with absolutely no original product ideas.

I’m sure the less capable companies will soon try to copy Biopellets but I think we hobbyists should try to support companies like Reef Interests as much as we can so that the art of reefkeeping moves forward.

Biopellets is made by Reef Interests and should be available in EU stores soon.

The cone: “Medium” from Aquarium Technik Burian (ATB)

ATB skimmers can be completely taken apart for cleaning

I finally got my new skimmer, model “Medium” from Aquarium Technik Burian (ATB). This is the first “high end” piece of equipment I’ve ever owned and I’m glad I did spend almost all my savings on this excellent foam fractionator. It is my opinion that most of the time the “high end” just means “more expensive” without any real benefit but in this case I was paying not only for the best performance in it’s class but also for a legendary customer service and support.

I’m so tired of the modern way of doing business where you must fight every step with companies when you try to solve problems or even to actually get your purchase you’ve paid for. Many times you just don’t get any help. This was once again my experience with ATI when I tried to find out what options I had to replace a pump that had just died on my ATI Bubble Master. This is the original model (without any number after the name) that used single, hand modified version of Eheim 1262 pump. The only source for this special pump would be ATI but the reply I got was “we did not produce the BM with the Eheim pump since a long time.” Well, great! Obviously I was going to change to other manufacturer that wouldn’t leave me with perfectly good skimmer body but no pump.

Anyways, enough ranting, let’s move to more positive things. First of all the performance of this modest sized skimmer is absolutely fantastic. I would say it removes at least twice as much organics compared to ATI Bubble Master 250. It is also very quiet and (needless to say) the fit and finish are first class.

Unlike some of the other skimmers I’ve owned, ATB doesn’t seem to be sensitive to small disturbances like placing your hand in aquarium. Naturally it will temporarily stop foaming if you add oils in some form into the aquarium but it is extremely fast to recover. Besides the raw performance, this must be one of the best features of the ATB conical skimmer. I feed invertebrates 4 times a day, about 30 minutes per feeding. The faster the skimmer can start to reduce the introduced organics after each feeding session the better. Previously, with the ATI skimmer, it would take anything up to one hour before the skimmer would start to skim again but with ATB Medium the time is measured in minutes. It is kind of strange to see skimmer to start producing foam that really shouldn’t “stick” and yet it shoots this mixture of oils and other such stuff into the collection cup in just a few minutes and then proceeds like nothing had happened except that the removal rate is much faster in the first 10-20 minutes after feeding. It is also very easy to monitor the performance of the skimmer because it has a drain; you can count the drip rate. At my setting the drip rate after feeding is 2 per second and as the water gets cleaner and cleaner it settles around one per 3 seconds.

I can sincerely recommend this protein skimmer for tanks around 200 gallons and larger. Be sure to check out ATB’s “econo” line also, I think you get mostly the same benefits at lower price. If the conical shape is responsible for the short recovery time after feeding like I suspect it is you might want to consider a cone as your next skimmer.

I think my tank is now ready for some new interesting animals from Mrutzek Meeresaquaristik scheduled to arrive this thursday

Tags: chemistry, equipment, food for thought, Husbandry, nutrients, tank

This entry was posted on Tuesday, September 22nd, 2009 at 23:34 and is filed under Husbandry, Ideas and misc. You can follow any responses to this entry through the RSS 2.0 feed.