Issues with sandbed despite 0 NO3 and PO4

[DrHollyW00D]

Hello, I am having this issue where these (what I think are Diatoms) are constantly appearing. Here are my parameters:
KH: 8.2 (Hanna)
Ca: 498 (Hanna, slightly elevated I stopped dosing for it to come back down)
Mg: 1305 (Salifert)
NO3: 2.5 (Salifert. I had them at 0 for a few months and the issue was still ongoing, I recently increased NO3 because I was advised that my coral might appreciate a "little dirty" water.)
PO4: 0 (Salifert)
I was originally told I was overfeeding so I adjusted drastically, to a point where I would only feed once every other day. Felt bad doing that to the fish but I wanted to see if I cut back for a few months if it would help, it didn't. I have a 50 gallon AIO tank with a tiny little refugium in one of the sections in the back with chaeto.
I will take any and all advice. Thank you in advance.

Edit: Tank has been running since October 2019.

 

[Dcal]

I think your nutrients are too low. Bottoming out at zero can cause diatoms, dinos and everything, which is why a lot of people warn to not overdose vibrant or other nutrient dropping chemicals. Id get them up a little bit any way you can but wait for someone else to hopefully back me up to make sure I'm not wrong

 

[CDavmd]

Likely Dino’s-

the 0 phosphate will allow them to take over because other competitors die out.
You need a microscope to identify them and confirm.

if they are swimming small golden ovals/sesame seed shape then it’s dinos. Needle like structures would be diatoms.

there is a massive thread on dinos- I’d go there and start by identifying if this is what you are dealing with.

 

[Dcal]

sweet rfa btw!

 

[DrHollyW00D]

I think your nutrients are too low. Bottoming out at zero can cause diatoms, dinos and everything, which is why a lot of people warn to not overdose vibrant or other nutrient dropping chemicals. Id get them up a little bit any way you can but wait for someone else to hopefully back me up to make sure I'm not wrong

Would RedSea AB+ be in that list of "nutrient dropping chemicals"? Maybe I need to stop dosing that for a while. I was able to increase my NO3. Any suggestions on how to increase PO4? Should I stop running my skimmer?

 

[Dcal]

Would RedSea AB+ be in that list of "nutrient dropping chemicals"? Maybe I need to stop dosing that for a while. I was able to increase my NO3. Any suggestions on how to increase PO4? Should I stop running my skimmer?

So i kinda was bottoming out too a couple weeks ago and my solution was halving the time my ATS light was on. If you're running refugium consider doing the same thing and there's some posts here about reducing the time skimmer is on I think as well

 

[Jekyl]

Would RedSea AB+ be in that list of "nutrient dropping chemicals"? Maybe I need to stop dosing that for a while. I was able to increase my NO3. Any suggestions on how to increase PO4? Should I stop running my skimmer?

Don't ever just stop running the skimmer. Either adjust it back or allow to drain back into your sump.

 

[DrHollyW00D]

sweet rfa btw!

Thank you! ;Happy Got it when it was about a quarter's size.

 

[Saltyreef]

Those are diatoms not dinos (as suggested)
They are there because they are feeding off excess silicate in your system.
Be it that from the sand (likely)
Or coming in from your water (if using 0ppm rodi this is less likely)

A good sand rinse will take care of this

 

[Thespammailaccount]

Would RedSea AB+ be in that list of "nutrient dropping chemicals"? Maybe I need to stop dosing that for a while. I was able to increase my NO3. Any suggestions on how to increase PO4? Should I stop running my skimmer?

No ab+ is feeding your corals I would not stop dosing with zero nitrate/phosphate. I have to dose phosphate or they bottom out

 

[Justdrew]

Would RedSea AB+ be in that list of "nutrient dropping chemicals"? Maybe I need to stop dosing that for a while. I was able to increase my NO3. Any suggestions on how to increase PO4? Should I stop running my skimmer?

AB+ adds to your nutrients.

 

[DrHollyW00D]

Likely Dino’s-

the 0 phosphate will allow them to take over because other competitors die out.
You need a microscope to identify them and confirm.

if they are swimming small golden ovals/sesame seed shape then it’s dinos. Needle like structures would be diatoms.

there is a massive thread on dinos- I’d go there and start by identifying if this is what you are dealing with.

I've always wanted a microscope. Any recommendations?

Gotcha, that makes sense. Any advice on increasing phosphate?

 

[DrHollyW00D]

So i kinda was bottoming out too a couple weeks ago and my solution was halving the time my ATS light was on. If you're running refugium consider doing the same thing and there's some posts here about reducing the time skimmer is on I think as well

Thank you!

 

[DrHollyW00D]

No ab+ is feeding your corals I would not stop dosing with zero nitrate/phosphate. I have to dose phosphate or they bottom out

Would you mind sharing which phosphate product you use?

 

[Thespammailaccount]

Would you mind sharing which phosphate product you use?

Brightwell aquatics neophos

 

[Saltyreef]

Would you mind sharing which phosphate product you use?

These are what i use

GLA Potassium Nitrate (KNO3) Aquarium Fertilizer - 1lb Jar

Green Leaf Aquariums Potassium Nitrate (KNO3) delivers vital nitrogen and potassium to fuel healthy, robust aquatic plant growth.

greenleafaquariums.com

GLA Monopotassium Phosphate (KH2PO4) Aquarium Fertilizer - 1lb Jar

Green Leaf Aquariums KH2PO4 provides phosphate and potassium to support strong root growth and photosynthesis in aquatic plants.

greenleafaquariums.com

 

[DrHollyW00D]

Those are diatoms not dinos (as suggested)
They are there because they are feeding off excess silicate in your system.
Be it that from the sand (likely)
Or coming in from your water (if using 0ppm rodi this is less likely)

A good sand rinse will take care of this

I don't think it's from my water, I use a RODI and the reading always says 0ppm. So the issue is coming from the sand itself? How do you recommend I wash the sand?

 

[Saltyreef]

I don't think it's from my water, I use a RODI and the reading always says 0ppm. So the issue is coming from the sand itself? How do you recommend I wash the sand?

Remove into a 5 gal pail.
Rinse with tap until it runs clear.
Then final rinse in RODI. Back into the tank.

Doing that before startup can really help with this issue later on.

 

[CDavmd]

Those are diatoms not dinos (as suggested)
They are there because they are feeding off excess silicate in your system.
Be it that from the sand (likely)
Or coming in from your water (if using 0ppm rodi this is less likely)

A good sand rinse will take care of this

You cannot distinguish diatoms from dinos by just looking at the sand.
Amphidinium can look exactly like diatoms. A microscope is needed to truly distinguish.
The tank has been running since October- silicates and diatoms should have run their course by now unless the water supply is adding ongoing silicates.

the zero phosphate raises a strong possibility of dinos. Again positive ID will require a microscope.

to the original poster- get a basic microscope on Amazon. Take some pictures and post them. If Dinos- again I suggest going over to the major Dino thread and reading the first few pages and follow @taricha advice. Get your phosphates up, start feeding more, and let things settle. You want to encourage algae growth. It will take time and patience.
Hopefully it is diatoms in which case you need to test your rodi water and eliminate the source.
best of luck!

 

[CDavmd]

Remove into a 5 gal pail.
Rinse with tap until it runs clear.
Then final rinse in RODI. Back into the tank.

Doing that before startup can really help with this issue later on.

If your water is 0ppm then this argues for dinos. Diatoms run their course early on, unless you are dosing silicates or continuously adding new sand, the silicates should be used up by now.
Washing the sand will not solve this problem.
Again before doing anything make a positive ID.