Macroalgae Nitrate Export
 

How fast will MNE take to occur...........Well Let's find out....sort of.

Tank 7"x7"x17"
Airline with valve
Terta Tec Deep Pump
Water volume = 3 gallons
Algae = Caulerpa and Chaeto

Setup
http://i635.photobucket.com/albums/u...g/IMG_2649.jpg

Day 1 - Noticeable change in Nitrate
http://i635.photobucket.com/albums/u...g/IMG_2651.jpg

I'd like to also know what ratio of phosphate and nitrate the chaeto consumes.

Do you have a phosphate test kit as well?

I'll watch this one... do you have turnover or is it just the closed tank?

Hi Megalodon, I managed to dig up my phosphate kit and will include as well.

http://i635.photobucket.com/albums/u...g/IMG_2652.jpg

Greenmaster, the algae scrubber is closed at the moment. I might wait till all nitrates are removed from the closed system before I introduce any flow from the display tank.

Let's say it takes 5 days to remove all nitrate from the 3 gallons. I'll set the flow to match that turnover. Don't think it would make any difference to the algae, but I would like to see if I can keep the effluent of the scrubber at O nitrates.......assuming it even works at all.

That sounds good but maybe not the best thing... Think of it this way. if you put a plant in a acrylic box and measure the amount of CO2 in it then seal the box and wait till all the CO2 is gone the plant won't be happy... then you determined the rate at witch it took CO2 out of the air and got the air to be pumped into the box at that rate your plant would have huge die off and not be able to remove as much as otherwise... on the other side if you were to give it elevated levels of CO2 it would take off and start to convert more CO2 then before.
Now with your experiment the plant will not die because you are providing CO2 but the nitrate/phosphate is what it uses to grow so you will have more growth in the beginning and less as the saturation drops. I like the idea of the experiment and would love to see the results but I believe that once you have determined the amount being removed you would be better off to allow high flow to make sure that the plants are getting as much access to the nitrate/phosphate as possible. When the plants take off you will need to prune them to ensure that they have space to grow.
A lot of people make the mistake of letting the plants grow till they fill the refuge and thing that volume helps with "cleaning" the water.
The other one is your idea, they think that the plant de-nitrate is the same as an aerobic where it is ideal to have the water come out the end at no nitrates. With plants however you will have good growth at the water entrance and less as it gets "eaten" by the plants at the far end you will have minimal growth on the plants as they are not getting the rich fertilizer.
I'm not trying to talk anybody down I'm just trying to help people understand the biology of the system and why it works. I'm more then willing to answer more questions... or if you want me to shut up I can do that too... I want to see how this experiment turns out :D.

One question... what lighting are you using? (plants need; CO2 provided by the bubbles faster is better... I would also put the bubbles at the bottom of the tank, nutrients provided by the fish nitrate/phosphate, and light, in order to grow well... more growth means more nitrate reduction)

At the moment the only lighting for the algae is an adjacent window, but I doubt if the tank is getting any direct sunlight though. Once I can get my hands on some rigid tubing (one of those boxes in the basement) I'll lower the airline and add a diffuser.

I'm regulating the flow to the algae scrubber, I'll call it that for now since there is no sand or rock that you might find in a typical refuge, mainly out of curiosity. However, I see your point with regards to providing a higher concentration of nutrients to promote growth, and subsequent uptake.

Add a light if you want to really have some proper nutrient export. Photosynthetic processes are what uses up NO3 and PO4, so you should add supplemental lighting.

+1

Day 2

http://i635.photobucket.com/albums/u.../IMG_26522.jpg
http://i635.photobucket.com/albums/u...g/IMG_2653.jpg

Coming along :D

Nice!

he will probably be updating within 1-2 hours :)

Day 3

http://i635.photobucket.com/albums/u...g/IMG_2656.jpg
http://i635.photobucket.com/albums/u...g/IMG_2658.jpg

Nice call!

Seen you update the same time every day... but you were early today :D

Looks like all the nitrate is gone after 3 days... not that great of a phosphate scrubber by the looks of it, did a little but not much... maybe it would have been better with more light... what was the size of your macro-algae ball? And I see the colors but what was the number for the nitrate for intro?

Very interesting. Pretty much what I would expect to see. I have done some research on terrestrial plants and for every 100 grams of N taken up only about 6.7 grams of P are used for growth with the caveat that all other essential nutrients are in adequate supply. I would expect that marine plants would have the same patterns of uptake but I could be wrong!

Traffic was a bit lighter today :biggrin:

Amazing that something so simple works so well, no messing with flow, anaerobic zones, advection, biodiversity etc. Not to say that I won't be trying other methods, but I may finally be able to start adding some corals to my tank soon.

I've turned on the maxijet connected to the tank to exchange water and start over. This time I've added a 13w compact fluorescent that I will run 24/7....lets see how it goes.

Current Setup
http://i635.photobucket.com/albums/u...g/IMG_2659.jpg

Difficult to get numbers from the API Nitrate test kit.

0-10ppm (shades of yellow)
20ppm (orange)
40-160+ (shades of red)

http://www.americanaquariumproducts....ratecolor2.jpg

There still is that phosphate problem though?

Hi Sunee, I wonder if the uptake of phosphates would increase if there was no Nitrate present?

I doubt it. Plants consume Nitrates as plant food, so no nitrates would mean your macroalgae would have a very hard time, NOT that your phosphate uptake would increase.

FWIW, when I ran my turf scrubber, {turf algae}, on my 225g, there was never any nitrate or phosphate that was measurable by me. The turf algae seemed to be very good at removing phosphate.

So you will be running it through your tank... and keeping us posted as to your levels right :D

Still going to be a closed system for know. Just interested in seeing how 24/7 lighting would compare to the previous 3 days using indirect sunlight, and will keep everyone posted.

nice :biggrin:

You're right, no nitrate no growth and no phosphate uptake. Actually this applies to any nutrient, if one of the elements essential for growth is not available the plant stops growing.

I have 0 detectible nitrates in my tank and lots of microalgae. Cheato, caulerpa (3 types) and when the nitrates are lower they grow slower, when there is more feeding and nitrates rise (still test at 0 on my tests) then I can see the caulerpa have quick and fast growth.

It just keep my aquarium without any detectible level of nitrates in the water and when the caulerpa grow too much I just prune it. I have some leave of caulerpa that are around 9 inches long now :)

Awsome tread, tagging along.

Here are the Day 1 results with 24 hour lighting.

http://i635.photobucket.com/albums/u...g/IMG_2662.jpg
http://i635.photobucket.com/albums/u...g/IMG_2663.jpg

I think I night have mixed up my samples earlier today, and the previous nitrate test does not seem to be accurate.

Here is what I just tested
http://i635.photobucket.com/albums/u...g/IMG_2664.jpg

Wow look at the diff a cheep light and some circulation made :D
Did you do the phosphates right though?

Phosphates are easily removed with ferric oxide though, and maybe it is more efficient than micro algae to remove phosphates?

GFO is so expensive though. I'm trying to wean my tank off it with chaeto however phosphates don't appear to be consumed as readily as nitrate. I hear it's the same problem with a carbon source, the bacteria consume nitrate and phosphates in a ratio that leaves excess phosphate. There's some reefers recommending to go back to bio balls because of this, LOL. I'm not sure if this is true or not. Oh well, GFO stays in my tank for now. So does the chaeto.

The NP biopellets work well but I agree that they take out more N than P, because of this I'm running GFO in a phosban reactor. Between the two I'm happy with my phosphate levels.
Levi

I wonder about that bio-ball theory. Some claim to have struck a balance by re-indroducing bio-balls (or other nitrate factories), which increases macro algae growth, or, skimmate with carbon source/bio pellets, and results in almost no phosphates or nitrates. It would save a lot of money on GFO if true.

Interesting? :twised:

Not entirely sure what has happened? The day 2 test using 24/7 compact fluorescent lighting showed an increase in the level of nitrate.

http://i635.photobucket.com/albums/u...g/IMG_2736.jpg

I may have botched the last series of test and the results somewhere are not correct, or there is some nitrate being released back into the system with 24hr lighting. I guess that is why many test are required before coming to a conclusion, which is why I'll not make any regarding 24hr lighting at the moment....more to come.

Regardless, I think I can say that Algal tests were positive overall and I will continue to use on my 75gallon. I've started continuous flow between the scrubber and DT using the MJ400 and will monitor growth and system nitrate in coming weeks.

Keep in mind that the tank has no other means of export at the moment in the form of a skimmer or water changes and there are no plans currently to start.

http://i635.photobucket.com/albums/u...g/IMG_2739.jpg

Day 2 - Didn't expect to much change

http://i635.photobucket.com/albums/u...g/IMG_2743.jpg

What the heck's going on?

Theory... All the pods and other critters in the algae started dieing after being removed from the main tank, thus resulting in the eventual creation of nitrates. Not sure if that's the case or not (or even possible) but thought I'd throw it out there anyway.

Not sure myself, and more test would be required, but there may be negative effects of running macroalgae lighting 24/7.

No too sure, but I run mine 24/7 in my sump & there have been no ill effects.

Many people run it 24/7, but many have switched to alternate lighting to the main tank in an effort to control pH swings created by CO2 caused by respiration of the macros.

I suspect the changes in water chemistry you are seeing from the closed system you have running there. It could be that the pods etc dieing as Mega suggested, or the cheato could be dieing as a result of a lack of nutrients and increased photocylce.

Andrew

One possibility is that there is inadequate CO2 to support photosynthesis with 24/7 lighting in your system. You could try changing to 18 hours light or increase flow to your algae tank which would hopefully increase the CO2 supply.

You could try many things but the important thing is that it works for you. Great test, I found it very interesting!