Nitrates and Phosphates too low

RobTorMar · Mar 30, 2021

Hello,

This has been discussed before but I just wanted to know a bit more of the chemistry behind it and get some advice. My tank is about ~4 Months old and the phosphates are consistently at 0.00 on the hannah checker and nitrates at 2.5 on the salifert. Now from what I've read, my understanding is that phosphates and nitrates should be a bit higher considering the tank is new and I run a cannister filter which is apparently not great at removing those compounds. I have a 55 gallon tank, I do 10g water changes weekly and clean my cannister filter religiously every two weeks. I have 1 xenia, 1 gsp, 1 trachyphyllia, 1 colony of zoas and 1 green tip torch. I also have two clowns, a cleaner shrimp and a turbo snail. I have very little algae growth on my rock or sand which must be a result of the non-existent phosphate. I've also been dosing half the recommended dose of MB7 for the past 2 months and run my t5s for ~6hrs/day . I spot feed my clowns and shrimp with a pipette (enough for them to eat in 2 minutes) and recently started spot feeding the corals as well once a week. I've read low levels like this is going to be a problem for my corals, I've been thinking of adding a flame hawk fish to increase my bio load, but afraid that the tank is still too new. What's the best way to fix these parameters without dosing any chemicals?

Spare time · Mar 30, 2021

Just feed more. That's the simplest solution. 2.5 nitrate is not bad but its hard to keep low levels stable without hitting 0.

You can also cut back on water changes but just monitor alk and calcium if you do not currently test those.

vabben · Mar 30, 2021

I'd ditch the spot feeding fish and shrimp and broadcast feed, it's just more practical in the long term. You could feed more or more often to help raise the nutrients in the tank. Also, as you mentioned adding more fish to the tank will help as well.

Not sure how much or how often you are dosing MB7, but this will also lower the nutrients in your system.

Alex Cataldo · Mar 30, 2021

Feed more and if you have too, dose nitrates and phosphates. But I would highly not recommend this since your tank is so young, and the uptake of these things in reality is not that much

RobTorMar · Mar 30, 2021

Spare time said:
Just feed more. That's the simplest solution. 2.5 nitrate is not bad but its hard to keep low levels stable without hitting 0.

You can also cut back on water changes but just monitor alk and calcium if you do not currently test those.

so instead of 20% should I do 10%?

Randy Holmes-Farley · Mar 31, 2021

RobTorMar said:
so instead of 20% should I do 10%?

Water changes are not generally a cause of nutrients too low. A 20% change on 2 ppm nitrate water only drops it to 1.6 ppm, and the effect on phosphate is even lower due to phosphate bound to rock and sand that comes back off after a water change.

I'd focus on feeding more or dosing.

RobTorMar · Mar 31, 2021

Randy Holmes-Farley said:
Water changes are not generally a cause of nutrients too low. A 20% change on 2 ppm nitrate water only drops it to 1.6 ppm, and the effect on phosphate is even lower due to phosphate bound to rock and sand that comes back off after a water change.

I'd focus on feeding more or dosing.

Do you happen to know if there is any sort of conversion from amount of food... say x grams of food can potentially produce Y ppms of nitrates or phosphates etc?

00W · Mar 31, 2021

Let the tank mature and enjoy what you have going on right now. Sounds like you have a great husbandry routine and I'm jealous. If everything and everyone is doing great why change what you are doing.
At least you are not pulling out GHA twice a week or have dinos, cyno or anything else like that.
Nutrients will come my friend. No worries.
Use only quality test kits and keep all your parameters in line. Calcium, KH, and potassium.
It will all align and then you might be posting other things....
Stay happy.
Joel

Reefahholic · Apr 1, 2021

Randy Holmes-Farley · Apr 1, 2021

RobTorMar said:
Do you happen to know if there is any sort of conversion from amount of food... say x grams of food can potentially produce Y ppms of nitrates or phosphates etc?

Yes, but it is not especially useful since if you try to raise phosphate with any method, most will end up bound to rock and sand surfaces.

That said, I show how much phosphate comes from how much of different types of foods here:

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com