Raising nitrate and phosphate without growing algae

[scottrotton]

Hi

I wanted to ask this question but I should give some background of my tank.

I used to dose carbon but bleached my corals because I could never get a reading of phos or nitrate. So I then decided to try a refugium which made my corals all colour up and start growing again for the last 6 months. I thought my narrates were consistently 3ppm but actually they are 0 after finding out I have a bad test kit.

My phos was 0.06 ppm
Nitrate 0

So I have been dosing nitrates. My phos dropped very quickly to 1ppb. One thing to note is I have to dose an extra 50% to stable my alk since dosing nitrate so it's been a massive limiting factor in my growth

So now my phos and nitrates are very close to 0. The more I feed to more algae I get and still no reading.

Sand bed is looking brown. Any suggestions?

 

[amazongb]

I went through the same thing. If that’s cyano, then it could be consuming your nitrates and phosphates.. which means, you probably do have nitrates and phosphates, but your tests won’t show it.. how’s your water change schedule? Do you vacuum the sand bed?

 

[scottrotton]

I dont really water change at all. Never have unless needed and because my nites are always 0 doesn't seem much point in changing the water. But I would if they were 5+ppm

Not sure if it's cyano looks more like diatoms to me but I'm no expert.

 

[Crashjack]

My guess is dinos. Many types of dinos thrive in low nutrient conditions. Unfortunately, there is no quick fix. I suggest you start here: https://www.reef2reef.com/threads/dinoflagellates-–-are-you-tired-of-battling-altogether.293318/

 

[biophilia]

What testing method are you using that's giving you a 1 ppb resolution for phosphate? Lots of tanks are successful with even "off the charts" levels of NO3 and PO4 without being overrun by algae, but IMO the key to keeping a successful tank with levels of macro-nutrients much above those found in seawater is lots of flow and maintaining a big population of micro-herbivores like hermits, anthropods, isopods, copepods, snails, etc. I keep a lot of hermits in my tank (about 1 per gallon of water) and find that the only place that I ever see algae despite dosing a lot of nitrate and silicate, feeding heavily, and not using GOFO is the one or two spots where the hermits can't reach. Occasionally, I'll pluck some algae off of those spots and drop it somewhere else in the tank and the hermits will make it disappear within 5 minutes.

That being said, there's a good chance your current bloom will pass on its own within a few weeks as your tank biota gets used to the fact that nitrate is not the limiting nutrient anymore and adjusts accordingly. If I were in your shoes, I'd try a 20% water change and pointing a powerhead closer to the sandbed and waiting a few weeks before doing anything more drastic.

Beautiful tank btw!

 

[scottrotton]

I use Hanna ultra low for phos and red sea pro for nitrate.

I'll get a few more powerheads and see if that helps. I have literally hundreds of baby snail over my glass each morning and the tank has been going for a year. 1 fighting snail and 2 sand sifting stars so I thought that would cover it. I may continue to dose nitrate until i get a reading along with lower refugium light settings. See if that fixes it

 

[scottrotton]

My guess is dinos. Many types of dinos thrive in low nutrient conditions. Unfortunately, there is no quick fix. I suggest you start here: https://www.reef2reef.com/threads/dinoflagellates-–-are-you-tired-of-battling-altogether.293318/

Could be Dino actually, after reading this. My tank meets all the requirements

 

[scottrotton]

Maybe @taricha can chime in and give an ID of what im dealing with?

 

[Lasse]

Your refugium has done its job, period. The things on the sand is what people normally see when the real levels of NO3 and PO4 is very near zero. These organisms can use other forms of N and P for growth. I do not name them because I´m not sure what it is in reality.

You have reach a stage of your reefing there your probably need to dose both P and N on a daily basis to keep it running well. The best way of doing this - for the moment - is to dose PO4 and NO3.

How to dose?

When you read x ppm NO3 and y ppm PO4 - what are you really measure? The answer - you measure the surplus of these two compounds - the amount not has been consumed by the photosynthesis or/and not has been depleted by other processes in your aquarium. If you take the measurement just before your light regim is at max. - you get the result of the photosynthesis daily work. If the values - during time - change in one or another direction - the daily nutrient flush through your system is to high or to low. See this post there I try to explain the different processes around P and N in an aquarium.

What´s to do in a situation like this? The way I would do it will be with daily dosing of PO4 and NO3. I would slowly rise the dose till i read figures of PO4 and NO3. Now - I know the extra daily supplement of PO4 and NO3 needed for my my aquarium. But its only a snapshot - the demand will vary. Therefore I would rise my figures to a safe level there I know that it will take some time before it will be zero again if something happen. At this stage of the aquarium´s life - zero readings is more of concern for me than to high readings.

My personal goal for my mixed system is around 0.05 - 0.1 ppm in PO4 and 2-10 ppm NO3. I do not panic if the figures will be higher - I only turn off the dosing and wait some days. If I need (according to PO4) i use some GFO (or Al based absorber).

I think that even ULN guys can use this method to handle their system too. When reading zero - just put in a daily dose that make them read a figure and stay there with the dose. They will not get any seat belts in this case but they will fix the extra daily flush of nutrients to their system. As I mention in my post at my build thread - there is other elements of concern. Elements that is difficult to measure with hobby test kit. For these - I test my system every 2-3 months with Triton and fix the issues coming up according to their instructions. the only element I dosing in the blind is iron. I put some in my top off water - calculated from my head as long as I do not see any readings of iron at my Triton tests - I am safe and I know I put in a daily amount of it.

Its important to take snapshots of PO4 and NO3 - if you are close to zero with your "safety" level - test more often.

I run without WC and therefore its important for me to chose a supplement method that include trace elements. in my case it is Triton core 7 but there is a lot of complete system out there that´s work. Chose a system that fit your mentality but the ICP tests is important if you run without WC.

Sincerely Lasse

 

[taricha]

Maybe @taricha can chime in and give an ID of what im dealing with?

I can say based on the tank setup and the nutrient situation that the brown things could be dinos, perhaps (less likely) diatoms, or some other benthic photosynthetic cells - cyano, chrysophytes etc. There's some tests that can be done without a microscope, laid out in the dino thread linked above. For definitive ID, microscope is required.
I think Lasse just gave you a great way forward at this point.
I will chime in on one thing: Clean up crew.

I have literally hundreds of baby snail over my glass each morning and the tank has been going for a year. 1 fighting snail and 2 sand sifting stars so I thought that would cover it.

Hundreds of snails on the glass is great, but sounds like they are snails that specialize in rockwork and maybe not so much on the sand. Sand sifting stars aren't even on the right team. Instead of being herbivores, they are predators of the sandbed community, in fact they likely eat the herbivores that would be helping.
It sounds like the only "CUC" that might actually be filling the niche you want is the fighting conch. It's great, but not enough. Actual true sandbed herbivores are great and should be carefully selected. My favorites are conchs, common cucumbers, cerith snails, and the invisible copepods, amphipods etc that show up on their own.

 

[najer]

Great advice on both counts above, I would add dove snails to the above cuc, they live in the sand and breed like crazy.

 

[Lasse]

I forgot to mention Clean up crew - as @biophilia state above Herimts is very useful and also the animals @taricha mention.

Sincerely Lasse

 

[sghera64]

Your refugium has done its job, period. The things on the sand is what people normally see when the real levels of NO3 and PO4 is very near zero. These organisms can use other forms of N and P for growth. I do not name them because I´m not sure what it is in reality.

You have reach a stage of your reefing there your probably need to dose both P and N on a daily basis to keep it running well. The best way of doing this - for the moment - is to dose PO4 and NO3.

How to dose?

When you read x ppm NO3 and y ppm PO4 - what are you really measure? The answer - you measure the surplus of these two compounds - the amount not has been consumed by the photosynthesis or/and not has been depleted by other processes in your aquarium. If you take the measurement just before your light regim is at max. - you get the result of the photosynthesis daily work. If the values - during time - change in one or another direction - the daily nutrient flush through your system is to high or to low. See this post there I try to explain the different processes around P and N in an aquarium.

What´s to do in a situation like this? The way I would do it will be with daily dosing of PO4 and NO3. I would slowly rise the dose till i read figures of PO4 and NO3. Now - I know the extra daily supplement of PO4 and NO3 needed for my my aquarium. But its only a snapshot - the demand will vary. Therefore I would rise my figures to a safe level there I know that it will take some time before it will be zero again if something happen. At this stage of the aquarium´s life - zero readings is more of concern for me than to high readings.

My personal goal for my mixed system is around 0.05 - 0.1 ppm in PO4 and 2-10 ppm NO3. I do not panic if the figures will be higher - I only turn off the dosing and wait some days. If I need (according to PO4) i use some GFO (or Al based absorber).

I think that even ULN guys can use this method to handle their system too. When reading zero - just put in a daily dose that make them read a figure and stay there with the dose. They will not get any seat belts in this case but they will fix the extra daily flush of nutrients to their system. As I mention in my post at my build thread - there is other elements of concern. Elements that is difficult to measure with hobby test kit. For these - I test my system every 2-3 months with Triton and fix the issues coming up according to their instructions. the only element I dosing in the blind is iron. I put some in my top off water - calculated from my head as long as I do not see any readings of iron at my Triton tests - I am safe and I know I put in a daily amount of it.

Its important to take snapshots of PO4 and NO3 - if you are close to zero with your "safety" level - test more often.

I run without WC and therefore its important for me to chose a supplement method that include trace elements. in my case it is Triton core 7 but there is a lot of complete system out there that´s work. Chose a system that fit your mentality but the ICP tests is important if you run without WC.

Sincerely Lasse

+1

I went down the same path as the OP. I added a macro algae ‘fuge, crashed my N and P then got cyano. I tried heavy feeding and adding aminos. Still no N and P. As Lasse says, the ‘fuge is doing its job.

So I started daily dosing N and P 2 weeks ago. It goes through swings where you start to see N or P on you Hanna ULR or Red Sea Pro and then nothing. Today I have 16ppb PO4 and just a smidge of pink in the Red Sea Pro (<< 0.25 ppm-NO3). I’m happy with that, corals are healthy and no algae in DT. I do have GHA in my frag tanks which are detritus traps (I need to fix this).

So, start daily dosing as Lasse said, but don’t expect your normal numbers for P and N. Just reading something is probably good enough to give corals health and the beneficial microfauna an advantage that will allow them to outcompete the cyano and diatoms.

 

[scottrotton]

Great information guys, as always thanks for you help and time spent writing those replies their in line with what i was thinking but Lasse goes into some great detail . I will go down the path of continued dosing of nitrate and phos if needs but i think that will rise one its own with heavy feeding. But before i do that i should really find out the exact type of algae im dealing with, if its sapping out all the nutrients in my tank it may not be dino but some other type, if thats the case dosing will just add fuel to the flame (correct me if im wrong).

I will have a look at Lasse post and if i cant decide without a microscope i should probably order one.

I do have another question though, do you suggest i reduce the cheato photo period from 16 hours to something less drastic like 4 so i don't have to dose as much? or keep it as it is and ultimately it will suck up all the N and P im adding each day?

 

[scottrotton]

BTW here are my ICP Results, i only got them last week by i sent nearly a month ago due to how long it takes to ship and process from here in Australia, they look pretty good except an issue with low nutes and also idodine!

http://lab.atiaquaristik.com/publicAnalysis/16532

 

[taricha]

Great advice on both counts above, I would add dove snails to the above cuc, they live in the sand and breed like crazy.

I had to look up Dove snails, as I wasn't familiar and I'm interested in any small herbivores that reproduce in a tank. Things that scale up to the size of the food available are real problem solvers in a reef tank.
I think what's being referenced is what's ID'd here as a columbellid snail. Also called dove shells, and sold as "mini strombus" - but they definitely aren't that.
Absolutely great. I got some from Indo-Pacific Sea Farms ("mini-strombus") and they are good grazers, reproduce insanely, go everywhere - though I'd say they spend less time in the sand, and I'd still prefer Cerith or true Strombus for pure sandbed work. I think their most preferred niche is grazing the epiphytes that grow on macroalgae.
awesome snails.

egg pouch on glass, and columbellid snail.
(sorry for thread hijack)

 

[scottrotton]

So I'm not sure how accurate the paper towel test is but after 10 hours it looks like this. Which indicates its not dinos and raising the nitrate will cause it to get worse?

 

[biophilia]

Glad it's not dinos!

I'd bet it's one of the many species of cyanobacteria taking advantage of the recent change in macro-nutrient availability. One of the issues you may be dealing with is the fact that algae and/or cyanobacteria will naturally bloom for a short time to take advantage of the fact that nitrate is no longer a limiting nutrient in the system... at least until things stabilize with the new nitrate levels. If the bloom were diatoms, it would be an easy fix because your cleanup crew would pick up the slack and you'd probably never even notice an uptick in algae other than perhaps a tiny bit more to clean on the glass.

Since you're not doing regular, high-volume water changes, your tank is almost certainly silicate-limited right now (those ICP results seem to confirm it). Silicate depletes extremely quickly in reef tanks (upwards of 50% drop per day according to tests run by Randy Holmes-Farley) so an established tank with a decent population of sponge growth in the rockwork basically has zero silicate without regular water changes. There seems to be (some) evidence that in the presence of silicate, diatoms can establish first and prevent cyano blooms, but in the absence of Si, diatoms are unable to grow and cyano is more likely to be dominant.

It's anecdotal, but I noticed a marked reduction in the dusting of cyano I would get on powerheads and the back wall when I began dosing silicate to maintain about 0.5ppm. I also noticed a drop in greenish algae on the glass, which was a surprise, and now only clean the glass every 3 days or so vs. almost every day before. May be worth looking into.

Here's Randy Holmes-Farley's article on the topic: https://www.advancedaquarist.com/2003/1/aafeature1

 

[taricha]

There seems to be (some) evidence that in the presence of silicate, diatoms can establish first and prevent cyano blooms, but in the absence of Si, diatoms are unable to grow and cyano is more likely to be dominant.

It's anecdotal, but I noticed a marked reduction in the dusting of cyano I would get on powerheads and the back wall when I began dosing silicate to maintain about 0.5ppm.

I have to say (anecdotally, as well) i always had recurring cyano patches, but ramping up silica dosing my cyano disappeared and has stayed gone for 2-3months now.
Not what i was anticipating, but yeah.
Btw, you say 0.5ppm - what species (Si?, SiO2?) measured with what kit?
I'm keeping mine 1-2ppm SiO2 measured with Hanna meter.

 

[biophilia]

I have to say (anecdotally, as well) i always had recurring cyano patches, but ramping up silica dosing my cyano disappeared and has stayed gone for 2-3months now.
Not what i was anticipating, but yeah.
Btw, you say 0.5ppm - what species (Si?, SiO2?) measured with what kit?
I'm keeping mine 1-2ppm SiO2 measured with Hanna meter.

I'm actually not using a test kit at the moment ;Nailbiting, but I do 25% weekly water changes, so figure I'm not risking much by guess-timating it. I dose enough Brightwell's SpongExcel once per week to add 0.8ppm (SiO2) according to the dosing instructions that come with the SpongExcel. I figure this is probably keeping the tank somewhere in the 0.5ppm-ish range. I'd like to bring it up over time to 1-2ppm, but probably won't do that until I get a test kit. I've basically just been watching sponge growth in the rock and keeping an eye out for diatoms (haven't seen any so far).

How often do you find you need to dose to maintain that level?