Nitrate problem

[CaptMac08]

Hello, New Guy here. I apologize in advance if this question has already been asked by someone. I am currently running a 75g reef with a Fluval 4 cannister filter. Recently my nitrates have spiked to 50. I have done several water changes ranging from 5g to 20g. Just this past Monday I did a 20g water change and changed out filter media and am still getting nitrate at 50. All fish, coral and sand sifting starfish seem to be thriving, however my snails and hermit crabs have all died. Below I will have my last two testing results. Any suggestions on what could be causing this or how to get the level down so that when I replace the crabs and snails I hopefully do not have this same issue?

12/26 and 12/30
Temp 78
Ph 7.8
Salinity 1.026
Nitrate 50
Nitrite 0
Ammonia 0.2
Alk 3.5dKh
Calcium 209/315

With the exception of the calcium as you can see the numbers remain consistent. The testing on 12/26 was done prior to a water and media change. I do not know when the nitrates started rising because my testing on 11/22 had the levels at 10. Due to being down with COVID for a month 11/22 was the last time I was able to test until 12/26. Like I said above all fish, coral and sand sifting starfish are thriving and not showing signs of stress.

 

[Biglew11]

12/26 and 12/30
Temp 78
Ph 7.8
Salinity 1.026
Nitrate 50
Nitrite 0
Ammonia 0.2
Alk 3.5dKh
Calcium 209/315

I only see one set of numbers here.

Yor calcium and alkalinity are extremely low. Or did you read meq/l for the alk? You need to test magnesium
Get magnesium to around 1350 ppm
Alkalinity to 7-11 Dkh or 2.5-3.9 meq/l
Calcium about 420 ppm

Also need to test phosphates with a hanna ulr phosphate or phosphorus checker. The bacteria that consume nitrates also need phosphates to consume the nitrates. If phosphates are zero you will need to dose or feed more to raise them. Target .03-.1 ppm.

 

[nereefpat]

How old is the tank?

Do you have lots of rock? Was it dry or live when you added it?

 

[CaptMac08]

How old is the tank?

Do you have lots of rock? Was it dry or live when you added it?

My tank is about 7 months old. I have 5 rocks in there and a ship wreck. Three of the five rock were live rock. Of the two that were dry one is purple rock that I was told was engineered specifically for coral. This rock was added when I added my coral at the beginning of November.

 

[CaptMac08]

I only see one set of numbers here.

Yor calcium and alkalinity are extremely low. Or did you read meq/l for the alk? You need to test magnesium
Get magnesium to around 1350 ppm
Alkalinity to 7-11 Dkh or 2.5-3.9 meq/l
Calcium about 420 ppm

Also need to test phosphates with a hanna ulr phosphate or phosphorus checker. The bacteria that consume nitrates also need phosphates to consume the nitrates. If phosphates are zero you will need to dose or feed more to raise them. Target .03-.1 ppm.

The one set is due to all numbers but the calcium being the same. The alkalinity was measured using Dkh. As far as the phosphates and magnesium I have not tested them as until this reply did not know that those areas needed to be tested.

 

[Uncle99]

What’s the timing on those deaths?
Are they new adds, or been there and just died?

Something doesn’t make sense to me in Nitrate.
You make a big water change and nothing happens to nitrate, 20g change (your incoming water must be 0 nitrates) would have lowered that 50 to say 35-40ppm.

Cannister filters can be used but the filter MUST be cleaned every few days, if not, at least every week, otherwise they are great at increasing nitrates.

 

[Biglew11]

What test kits are you using? If magnesium is low it can allow calcium and alkalinity to precipitate. Are you dosing alkalinity and calcium to keep the numbers even. 50 ppm nitrates is getting high but I'd be more concerned about getting the other parameters in check first. Alkalinity at 3.5 dkh is extremely low. Surprised anything is surviving.

 

[nereefpat]

My tank is about 7 months old. I have 5 rocks in there and a ship wreck. Three of the five rock were live rock. Of the two that were dry one is purple rock that I was told was engineered specifically for coral. This rock was added when I added my coral at the beginning of November.

More rock, as it matures, will reduce the nitrate be means of anaerobic bacteria. 7 months is a new tank.

The canister filter may or may not be helping.

 

[YankeeTankee]

Continue water changes, in the future test more frequently and compare those results to ideal ranges. Clean out socks, filters.