Falling nitrates

Stewchi16 · Feb 9, 2023

Posted this in my build thread. Tank is 1 year old. Nitrates have been llowering. Phos is stable at 0.4. Nitrates went from 10 to 5 to 1 over past 2 months. I’ve had a small bit of bubble algae and bryopsis that is improving or stable. Corals are happy. Fish are fed flakes in morning and rods food in pm. I don’t rinse the rods food. Not really any gha. Just small green coloration to rocks. Coralline showing up on pumps and frags. Water change every 2 weeks. 10-15%
Had Dino’s a year ago. Should i stay the course or try to raise nitrates?

Timfish · Feb 9, 2023

Corals have symbiotic diazatrophs that convert N2 into NO3 so I wouldn't worry about it too much. But if you decide you want to see some trace amount feeding your fish more is the best way to do it.

bushdoc · Feb 9, 2023

I would think about raising nitrates, but don't go overboard. There is a group of reefers running Ultral Low Nutrient System. If you want to do that, you should also adjust other params as ULNS runs better with lower dKH. Otherwise I would try raising Nitrates more natural way: lower skimmer settings or run it intermittently, change filter socks less often, remove excess biomedia etc.

Idech · Feb 9, 2023

I’m no expert but I dose nitrates and phosphates to have nitrates around 10-15 ppm and I still get dinos. I’m thinking about stopping to see if it helps, or makes no difference.

bushdoc · Feb 9, 2023

Idech said:
I’m no expert but I dose nitrates and phosphates to have nitrates around 10-15 ppm and I still get dinos. I’m thinking about stopping to see if it helps, or makes no difference.

Dinos usually gets out of control in low nutrients tanks, but once established adding Nitrates only fuels their growth.

Idech · Feb 9, 2023

bushdoc said:
Dinos usually gets out of control in low nutrients tanks, but once established adding Nitrates only fuels their growth.

My tank is 16 months old. It might be considered low nutrients because I only have 3 fish (75 gallons). I used to have 7; most died and the dinos came back.

bushdoc · Feb 9, 2023

Idech said:
My tank is 16 months old. It might be considered low nutrients because I only have 3 fish (75 gallons). I used to have 7; most died and the dinos came back.

Research some post here how to fight Dinos. There are many ways. I am fortunate enough ( so far), I never had Dinos, so I have no personal experience fighting them.

Idech · Feb 10, 2023

bushdoc said:
Research some post here how to fight Dinos. There are many ways. I am fortunate enough ( so far), I never had Dinos, so I have no personal experience fighting them.

Oh I know how. I’ve had to learn since I’ve had them for almost a year now.

I was winning but losing my fish brought them back.

Spare time · Feb 10, 2023

Timfish said:
Corals have symbiotic diazatrophs that convert N2 into NO3 so I wouldn't worry about it too much. But if you decide you want to see some trace amount feeding your fish more is the best way to do it.

I am not sure if most hobby specimens have those as it should vary by environmental conditions. I also do not think (based off of my brief read of Bednarz et al. 2017) that is is something to assume all coral species exhibit this behavior. I am also not sure if they are even present in aquarium water, and if so, they may be limited due to actions like skimming. I'll have more time to read more papers (and more thouroughly) tomorrow so I may be able to update this.

Timfish · Feb 25, 2023

Spare time said:
I am not sure if most hobby specimens have those as it should vary by environmental conditions. I also do not think (based off of my brief read of Bednarz et al. 2017) that is is something to assume all coral species exhibit this behavior. I am also not sure if they are even present in aquarium water, and if so, they may be limited due to actions like skimming. I'll have more time to read more papers (and more thouroughly) tomorrow so I may be able to update this.

I agree, environmental conditions as well as both coral ans zooxanthellae species and genotype/clade are all variables. Considering how widespread diazotrophs are, they maybe endoliths (inside the coral skeleton) maybe part of the a coral's surface microbiome or found internally and as such are symbionts like zooxantheallae are and can provide an animals coloration.

One of the worrying issues is they've been linked to sugar (carbon dosing) induced bleaching in corals.