Turf scubber?
- Thread starter Brass sliver
- Start date
If you are talking about an algae turf scrubber, it is a shallow tray or basin that has mesh screens stretched over plastic frames. The The tray is then provided with intense illumination for 12 to 18 hours a day. Filamentous algae is then allowed to grow on the screen at the bottom of the scrubber tray. The water depth is from the algae is usually about 1/2 to 1 inch or less. Water is then passed over the tray in a wave like motion and this is usually created by using Dr Walter Adey's patented dump bucket. The growing algae crop removes nutrients, carbon dioxide, and metals from the water, and at the same time oxygenates it.Brass sliver said:
It is possible to build it but you would have to be good with tools a math(To build the dump bucket is the hardest past, I mean getting it balanced).
This is a pic of my scrubber.
Yes I am.
Does it reduce the frequency of your water changes? If I understand it outcompetes the algea in the tank sucking up all the available nutrients starving the algea. right? Is it harder to grow plants then? I need a little more info on what it does.
Does it reduce the frequency of your water changes? If I understand it outcompetes the algea in the tank sucking up all the available nutrients starving the algea. right? Is it harder to grow plants then? I need a little more info on what it does.
Brass sliver said:
This could be debated, in the book by Dr Walter Adey it is debated that an algae scrubber can maintain a closed system ,using the scrubber to export nutrients by means of removing the algae from the scrubber/system, meaning that water changes are not generaly needed like a traditional filtration system. Obviously evaporation occurs so the water has to be replaced, but they use deionized water for replacement, it is also recomended to do very small water changes 5% be done at intervals(time frame does vary with this). I went almost a year using this regime without any problems(lately I have been doing more water changes I must add). It dose not necssarily outcompete the algae in the main tank ,but the conditions in the scrubber are preferable as opposed to the main tank, but then it dose not allow it to become a problem either. I have not had any problems with algae yet, my nitrates are less then 0.2 ppm(cant measure lower than this).
Yes I have found it harder to grow plants but the reason being is because I don't use any ferts, theoreticaly speaking higher plants should outcompete for nutrients and this would only improve the conditions of the water(lower nutrients).
It is not the prettiest filter and you have to take out the screens every 7-14 days and scrape the algae off them, but that should only take a few minites, the other thing is that the dump bucket is pretty load, but if these things dont bother you it is a pretty good filtration method.
If you can get hold of a Dyanamic Aquaria it has some good pics that you could use to build a dump bucket. Other than that it is basicaly is a acrylic bucket with a lip to over balance when it becomes full, this bucket is on hinges at both ends placed at the center of gravity point. I will try to get a pic if the one provided is not good enough.
In FW, an emerse veggie filter is far more efficient in nitrate export, and likely in the utilization of other nutrients as well, along with some pollutants. It also can be dead easy, and does not stink or make noise. Go to The Krib for hints on possible set-ups, or maybe Tom Barr's site.
Veggie fiters are generally used where the main display cannot be heavily planted. They are not very compatable with a planted tank as there is competition for nutrients there.
Veggie fiters are generally used where the main display cannot be heavily planted. They are not very compatable with a planted tank as there is competition for nutrients there.
RTR said:
RTR just curious, but could you tell me why you think vegie filters are more efficient at nitrates exporting. If you are talking terrestrial plants , I am under the understanding that they prefer nitrates over ammonia, But even then this uptake is much slower than algae. I believe you know that most aquatic plants and algae for that matter prefer ammonia over nitrates as a nitrogen source, taking up this form of nitrogen 4 times faster then when nitrates are most abundant. According to what I have reserched nothing comes close to micro algae for speed of nitrogen uptake, not even macro algae(this backed up by a few well know people). Higher plants require time to process these nutrients and form the complex stuctures that they are made of, on the other hand algae is a simple structure much more capable of using available nitrogen for fast growth(I have actual data on this just not on hand right now). I am really interested as to who your sources are , and if I am being misinformed by Dr Adeys and others reserch I would greatly appreciate for you to inform me of your sources and information. We may be going over old ground here but I am purely trying to get the correct facts here and would appreciate your imput very much.
My general impression of Algae scrubber filters is that they make a great deal of sense for large volume tanks - where the ammonia/nitrite conversion efficiency of the algae versus bacteria can process large volumes of water with a much lower 'real estate' requirement. Algae scrubber filters also provide for nitrate absorption, which bacteria do not, thus vastly reducing the fresh water change volumes necessary to keep nitrate buildups reasonable. Algae scrubber filters also provide for metals/toxins absorption, which bacteria do not in any significant degree.
The tradeoff with algae scrubbers is that they are 'ugly', and that they do require 'hands on' maintenance.
Thus with a 300+ gal tank volume, use of an algae scrubber filter could mean the difference between say 15 gal vs 75 gal water changes to keep nitrites down, would mean not having to run a carbon/chemical filter (or run a much smaller one) to keep metals/toxins down, and would mean the physical size of the algae scrubber filter would be signicantly smaller than say a wet/dry biological filter using bacteria capable of treating that volume of ammonia and nitrites, such that thinking about an algae scrubber filter starts to make sense. With an 1850 gal tank volume, these differences have MAJOR impact (I can hardly imagine the component sizes necessary to mechanically, chemically and biologically filter 10,000 gph of water, plus change out 500 gallons at a whack)! However, with a 55 gal tank volume, these differences are of much less significance, given a 500gph water flow to treat and a water change volume of 15 gal.
The tradeoff with algae scrubbers is that they are 'ugly', and that they do require 'hands on' maintenance.
Thus with a 300+ gal tank volume, use of an algae scrubber filter could mean the difference between say 15 gal vs 75 gal water changes to keep nitrites down, would mean not having to run a carbon/chemical filter (or run a much smaller one) to keep metals/toxins down, and would mean the physical size of the algae scrubber filter would be signicantly smaller than say a wet/dry biological filter using bacteria capable of treating that volume of ammonia and nitrites, such that thinking about an algae scrubber filter starts to make sense. With an 1850 gal tank volume, these differences have MAJOR impact (I can hardly imagine the component sizes necessary to mechanically, chemically and biologically filter 10,000 gph of water, plus change out 500 gallons at a whack)! However, with a 55 gal tank volume, these differences are of much less significance, given a 500gph water flow to treat and a water change volume of 15 gal.
Vascular plants "prefer" ammonia, just as do algae as it is more energy-efficient, but can utilize nitrate at a small energy cost. All vascular plants and algae require time to build their structures and cells, that difference is trivial. If you track export nitrogen export, the emerse vascular plants will win hands down over the algae because they are never carbon-limited (unlimited CO2 in the air), as aquatics commonly are (whether vascular or simple).
I've run emerse and submerse/immerse vascular plants as well as FW and SW algae scrubbers. For ease of operation and maintenance, emerse is always far easier and generally equally far better. For some situations I do use submerse veggie filters, where emergent plants would be visually or spacially obtrusive. Those cases are still higher plants (some barely so - Java Moss is one), as the upkeep and setup (light and current) is easier than for microalgae.
But all the systems can and do work. They are fun and interesting and challenging to assemble and troubleshoot. But for FW tanks, if I want a workhorse, I set for emersed vascular plants which can function as bog plants without the bog soil.
BTW, my central system has 2 veggie filters, a 20-long with emergent Crinums and 4 ea. 34W T5s, plus a 40-long sumerse vascular veggie filter with 2 ea. 40W T12s. The system is about 300 nominal gallons total.
I've run emerse and submerse/immerse vascular plants as well as FW and SW algae scrubbers. For ease of operation and maintenance, emerse is always far easier and generally equally far better. For some situations I do use submerse veggie filters, where emergent plants would be visually or spacially obtrusive. Those cases are still higher plants (some barely so - Java Moss is one), as the upkeep and setup (light and current) is easier than for microalgae.
But all the systems can and do work. They are fun and interesting and challenging to assemble and troubleshoot. But for FW tanks, if I want a workhorse, I set for emersed vascular plants which can function as bog plants without the bog soil.
BTW, my central system has 2 veggie filters, a 20-long with emergent Crinums and 4 ea. 34W T5s, plus a 40-long sumerse vascular veggie filter with 2 ea. 40W T12s. The system is about 300 nominal gallons total.
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Thanks for the reply RTR. Please do not misunderstand what I am trying to do here, I am not trying to prove you wrong, I am just trying to obtain the facts . I would like to quote a passage out of Dyanamic Aquaria in regards to algae production, Quote "Their actual tissue production rate is 5-20 g dry weight per square meter per day, a rate several times that of most terrestrial plants, including carefully tended agricultural crops. Algae, in a well-developed turf, can absorb typically 0.3 to 1.2 g N per square meter of screen, even in a low nutrient environment." End quote. I suppose you could then assume that from this that algae has a nitrogen uptake that far exceeds higher plants.
Another quote regarding algae, quote " Another reason for the unusually efficient growth of these algae lies in their structure. The algae filaments are to a large extent simple strands, not differentiated into specialized forms or functions. Most cells in the plant mass are photosynthetic, absorbing light, carbon dioxide, and nitrogenous and phosphorus compounds, and producing oxygen and carbohydrates. In contrast, larger more complex plants reserve much of their body for other functions such as structural support, reproduction, and protection, leaving a smaller proportion for photosynthesis." end quote. This is the reason why I chose to implyment the algae scrubber. I agree with you that they can but a chore an require constant attention to the conditions they are in , or production rate will fall. They are unsightly and can be messy, but from what I can gather micro algae is at the moment the most efficient at nutrient reduction. I have also read that they are not practical for smaller aquaruims, this however I tend to believe is true. Not for the reason of nutrient reduction rates but purely because it would be hard to maintain balance in a smaller body of water. Lack of Co2 in a water body can be easily overcome with bubbling of Co2, but even then there are other forms carbon that can be easily obtained by algae, but should be monitored regularly to guard against deficiencys. So I don't believe that Co2 should pose any problems.
Lately a lot of marine aquarist's have been turning to algae for filtration, using the principles that Dr Adey has writen is his book, some have chosen the 24/7 lighting approch using macro algae, and some have chosen different ways , but most people tend to stay away from the scrubber for some reason or another. Whether this is due to lack of information or due to misinformation I really don't know , all I can say is it works for me. Some poeple don't like using algae b/c of its leaky nature ,but jmo if contermeasures are taken it is relatively simple to overcome the minor problems they pose. Like yellow water and DOC's .
After listening to your information on veggie filters I am going to set one up in a 50g or 100g tank to see with my own eyes what emersed vascular plants can do. Do you use that as your only filtration or as a supplementary filter? And as I dont live in the states could you give me some names of emersed plant that will work most effectively. Also what substrate and water depth do you use?
I have to add that I tend to believe what Dr Adey has writen in his book b/c as you may know that his field of expertise is in algae, the scrubber is something they have developed along the way.
And Melonie thanks for you imput.
I would like to quote a passage out of Dyanamic Aquaria in regards to algae production, Quote "Their actual tissue production rate is 5-20 g dry weight per square meter per day, a rate several times that of most terrestrial plants, including carefully tended agricultural crops. Algae, in a well-developed turf, can absorb typically 0.3 to 1.2 g N per square meter of screen, even in a low nutrient environment." End quote. I suppose you could then assume that from this that algae has a nitrogen uptake that far exceeds higher plants. Another quote regarding algae, quote " Another reason for the unusually efficient growth of these algae lies in their structure. The algae filaments are to a large extent simple strands, not differentiated into specialized forms or functions. Most cells in the plant mass are photosynthetic, absorbing light, carbon dioxide, and nitrogenous and phosphorus compounds, and producing oxygen and carbohydrates. In contrast, larger more complex plants reserve much of their body for other functions such as structural support, reproduction, and protection, leaving a smaller proportion for photosynthesis." end quote. This is the reason why I chose to implyment the algae scrubber. I agree with you that they can but a chore an require constant attention to the conditions they are in , or production rate will fall. They are unsightly and can be messy, but from what I can gather micro algae is at the moment the most efficient at nutrient reduction. I have also read that they are not practical for smaller aquaruims, this however I tend to believe is true. Not for the reason of nutrient reduction rates but purely because it would be hard to maintain balance in a smaller body of water. Lack of Co2 in a water body can be easily overcome with bubbling of Co2, but even then there are other forms carbon that can be easily obtained by algae, but should be monitored regularly to guard against deficiencys. So I don't believe that Co2 should pose any problems.
Lately a lot of marine aquarist's have been turning to algae for filtration, using the principles that Dr Adey has writen is his book, some have chosen the 24/7 lighting approch using macro algae, and some have chosen different ways , but most people tend to stay away from the scrubber for some reason or another. Whether this is due to lack of information or due to misinformation I really don't know , all I can say is it works for me. Some poeple don't like using algae b/c of its leaky nature ,but jmo if contermeasures are taken it is relatively simple to overcome the minor problems they pose. Like yellow water and DOC's .
After listening to your information on veggie filters I am going to set one up in a 50g or 100g tank to see with my own eyes what emersed vascular plants can do. Do you use that as your only filtration or as a supplementary filter? And as I dont live in the states could you give me some names of emersed plant that will work most effectively. Also what substrate and water depth do you use?
I have to add that I tend to believe what Dr Adey has writen in his book b/c as you may know that his field of expertise is in algae, the scrubber is something they have developed along the way.
And Melonie thanks for you imput.