Phosphate using plants?

[Plantbrain]

Refuges can turn into their own little monsters as well...............

They need fed the right items to take care of the main tank properly and efficently.

Marine planted tanks in their own right also need these same things and are a good way to learn and understand them better.

I'll post a Cynao removal method that is from some Cyano inducement studies I've done in another thread.

Regards,
Tom Barr

 

[Fredfish]

OK, finally remembered to get that phosphate test kit. As you suggested and I suspected, phosphates show up as zero. Guess I will also be dosing part B of my f2. I expect it will have an N ration of 16:1 so it should work well.

modemfox. It will be interesting to see if or how quickly your cyano grows back. Let us know how it goes.


Fred

 

[Plantbrain]

Be gentle and cautious with the PO4, diatom bloom means too much. Pulse the dosing(say add 0.2ppm once and see hwo long it takes to be removed(few hours). You should see a decline in the NO3 as well over the next week.

We can add NO3 liberally, but more care is needed with PO4.

Regards,
Tom Barr

 

[modemfox]

Well i got the cyano back in the last 2 days. And brown algae everywhere in the fuge like overnight but none in the display tank again. I think it has something to do with my water change water. I was doing great and then i changed my water (30%) and all of a sudden I have the cyano problem all over again. I have tested the rodi machine i use and it is 0 TDS so this makes no sense. So what i figure i did was accidentally drop nitrates again but i figure phosphates would drop with a water change too. I don't get this stuff. Whats really strange is with the amount of macro's i have i shouldn't be seeing this at all. But I also only have 2 kinds now. I have caulerpa racemosa and caulerpa mexicana. I haven't had them go sexual so i have about 1 pound of each in my fuge with plenty of room to grow but very little growth. I do have a few test sea grasses with little or no growth and i have tried cheatomorphia but it won't do anything but get cyano on it. I'm stumped. Any ideas?

 

[modemfox]

Do you think maybe i can put a peice of shrimp in my system to rot and maybe get nitrates that way without phosphates?

 

[Plantbrain]

Just use KNO3, you can get it at Home Depot etc.

Then you can estimate precisely how much ppm of NO3 you add.

Also, adding shrimp adds NH4 first, then NO3, NH4 is a great way to culture microalgae...........


Regards,
Tom Barr

 

[Fredfish]

Hmm. My understanding was that cyano blooms are triggered by rising NH4, nitrite. Is it possible that there is amonium or nitrite in the water change water?

Plantbrain, can a cyano bloom be triggered by just falling nitrates?

Fred.

 

[modemfox]

I tested my water here are the results:

PH: 8.3
SAL: 1.026
Ammonia: 0
Nitrites: 0
Nitrates: 7ppm
Phosphate: .2ppm
Calcium: 360 (trying to get it up having a hard time)
Magnesium: 1360

I just hooked up my magnum 350 canister filter with diatomic powder and the micron filter and ran it about an hour and then used it to suck out the little cyano that was growing (Mostly on the caulerpa's in the fuge.) So with that i am down to no visable cyano again. I have got to find the secret to this crap its ticking me off.

 

[Fredfish]

Yea, its bizzare. I found out my phosphates were zero so I dosed a little phosphate yesterday and a little again today. Now the cyano is dying back again.

I am beginning to think that it has more to do with the macro growing well than what you add to make the macro grow. Possibly alleopathy. There are some fresh water plants that produce anti-bacterials. Maybe the Macros produce something to inhibit cyano growth, but only when they are growing properly.

Fred

 

[Plantbrain]

You can easily rule out allelopathy: add activated carbon which will remove allelopathic chemicals.

This obersvation of good plant growth is seem in not just with Caulpera, but with all plant and larger macro species.
What are the odds that some 50 species of macro/plants all have the same allelopathic chemical, amount produced and impact on the other algae?

Billions or more to one.

The best theory I've suggested is one based on NH4, healthy macro's/plants, remove most all the NH4 in the water column.

When the level of NH4 rised, that tells the noxious BGA, micro algae etc that it's a good time to grow since no one else is there or is dying.

Sort of like seeds when there is no water, they do not grow and germinate, when the rains do come, they grow like mad.
This appears to be true in FW as well as Marine systems.

PO4 also seems to be one that tells some algae to grow also more than in FW if there is enough for the diatoms to detect.

NH4 is like candy and means a lot more than NO3 to a smaller alga than a much much large one with lots of reserves.

When an algae is induced to bloom is a key question, why and when would an alga bloom?

What triggers it?

So you simply isolate and add things you think will cause a bloom.
I use to think it was high DO levels, but that proved incorrect, I added pure O2 to get 150% stauration. Did not help.

Low/absent NH4 sure seems to be the clear winner.
But there are combo's I have not tested either.
I basically rule out everything else and the one you are left with is often the cause.


Regards,
Tom Barr

 

[Fredfish]

The best theory I've suggested is one based on NH4,

My NH4 does not appear to have changed much at all since I started measuring nitrates etc. It measured at .1 back around March and then dropped off to not quite zero around May/June. That is as accurate as my seatest gets. Perhaps the nitrite trigger is lower than this, or the kit is not that accurate.

On another note, I decided to start actively feeding the amphopods in my refugium with some ground up flake/pellet food. Added a pinch last night and this morning my phosphates had jumped from undetectable to 1ppm. Wow! It had backed off to slightly over .5 by the afternoon. Thats a drop of about .4 over 4-5 hours.

I may give this another go with some better quality food (I just used what I had on hand) but I may have to re-think this feeding idea.

The cyano continues its decline although not as rapidly.

I agree it is highly unlikely that every macro produces the same allelopathy chemicals. do macros and cyanobacteria often bump up against each other in natural settings?

Fred

 

[Fredfish]

Holy nitrates batman!!! I decided to do a quick nitrate test before bed to see where things sat. Yesterday it was around 2ppm without any dosing. I figured this was from the pinch of food I added to feed the pods.

Tonight it sits at 20+??? Its hard to believe this comes from a pinch of dry food. Do dying cyanobacteria release significant amounts of nitrate?

Nitrites are up slightly at between .1 and .5 ppm.

Fred.

 

[modemfox]

Well i ordered an ozonizer just to test a theory. I beleive there is something in the water that we are not testing for that is fueling the cyano. What i don't understand though is i always hear about how real reefs are so whats the word, "sterile" with nothing as far as nitrate and phosphate readings. But if when you get that low cyano builds why doesn't it happen on the reef? It always seems to happen in the bays and inlets where all the caulerpas and sea grasses grow. Ever notice that? I live in a red tide area and this sorta got my attention when i started having problems.

I am starting to beleive if you have zero readings you should pull the macros to stop the cyano. (Which gives me and idea!) I might just empy my fuge and see what happens to the cyano since it wants to grow directly on the caulerpas. This just seems to much of a coincidense.(spelling, never had to type that word before! LOL!)

 

[Fredfish]

i always hear about how real reefs are so whats the word, "sterile" with nothing as far as nitrate and phosphate readings. But if when you get that low cyano builds why doesn't it happen on the reef?

Just because our test kits read zero dosn't mean there is no phosphate in the water. Hobby test kits are not particularly sensitive.

Phosphates and nitrates are a factor of 10 or 100 lower on reefs than they are in our tanks. I seem to remember some research experiments where phosphates and nitrates were dosed in open ocean areas to stimulate phyto blooms. At readings of .00x ppm for phosphates and nitrates (where x is a number somewhere between 2 and 9) phyto began to bloom.

Even the most nutrient poor aquarium has high phosphate and nitrate levels compared to reefs and open ocean.

When the cyano is growing on your caulerpa, is the caulerpa also still growing, or has it stopped?

I seem to remember plantbrain mentioning that macros can leak NH4 particularly when they are dying back. I wonder if this was the situation in my tank. My caulerpa had stopped growing adn looked to be slowly dying (leaves browning, showing ragged edges...). I think that is when the cyano started o overgrow my caulerpa.

Since bumping up the phosphates, my macros look much greener again and have begun to grow and the cyano is dying back.

Fred.

 

[Fredfish]

OK, I decided to run a reference test for my nitrates. I also ran another test of the tank next to it. The reference (10ppm) and my tank test look the same shade of pink, what I took to be 20+ppm. The tank test might be just a shade darker, so my nitrates are actually closer to 10ppm.

Fred

 

[Samala]

Isnt it amazing how far off they can be Fred? I'm glad you made a reference solution. I check mine against test results almost every time I run nutrient tests.

Pelagic phytoplankton species are super super sensitive to available nutrients in their environments. Because the open ocean is so nutrient poor they have to be very adept at finding and uptake the goodies before someone else does.

One of the coolest things I've ever seen is the pictures taken of the ocean after a hurricane has been through the area. As it moves it churns up the layers of ocean water underneath exposing deeper more nutrient rich layers to the upper layers where the phyto's can access it along with the sunshine. You see this green wake after the storms go through.. really neat. I think NOAA posts them on thier website.. I'll see if I can find the link.

 

[Plantbrain]

At least marine folks are privy to inaccurate test kits.
I have a C200 colorimeter and some real nice stuff at our lab for analysis, Mass spect, AA, Spects and more spects.

I like having accuracy down in the 0.01ppm range.

Another issue with low level test, the plant/alga may get it before you have a chance to measure it.

So as one plant wanes, and is decomposed slowly, the Nitrogen is being reassilimated so fast, it never builds up in the water column.

Ahhh, but there is a way around this problem............
Use N15 enrichment studies, we use a heavy isotope, N15 and then remove the plant sample after a time peroid of exposure, see how much was taken up, add some ratio factors for discrimnation, take in account the residual N in the tank prior and then we will get an estimation of who gets what over a time peroid.

Pretty cool.
P, C, O and Fe can also be done this way.

Not cheap and not something a hobbyists will do though.........but it would go a long way to answering the question and proving some of my theories.

I'll get around to it at some point.

Some day

Regards,
Tom Barr

 

[Fredfish]

Damn you have some cool toys!

Fred

 

[Plantbrain]

The ironic thing is I'm best known for not using test kits and avoiding them and being critical of them.......

That's because I have done lots of testing in the past.......and try to avoid it as a routine............but I like to test to answer a specific question.............

Way too many aquarist think testing is a good "routine" and that they will learn something great and grand for a routine of testing.

While there is some argument to this.............I think a purpose driven experimeent is much better and can answer things to make your life much easier............

I like to test why an algae grows by adding X nutrients etc.
I do not like to chase nutrients after the fact and the algae has already bloomed.

There are a lot more variables attempting to measure something after the fact...often the nutrient of interest is gone, or we cannot measure it acurrately, or cannot measure it at all........

I'd much rule things out step wise with a test kit than use them often for day to day routine maintenance.

The plants/macro algae are the best test kit anyway.......a bioassay.

Regards,
Tom Barr

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[Fredfish]

I hear ya. I hadn't owned a test kit for at least 5 years until I decided to start dosing nitrates.

As you say, they are usefull as a diagnostic tool.

I happen to have a seahorse fry tank floating inside my refugium and have been doing water changes into the refugium. Three days of this and my cyano is growing again, so I decided to test nitrite in the fry tank.

Yikes, its up at the top end of the test! Well, thats probably not saying much as the kit is off for nitrates, but still, the fry tank is a significant source of nitrites for the main system. Enough to keep nitrites up at around .5ppm and make my cyano fat and happy. I think I need a biowheel for my fry tank.

Fred.