Hammer and Duncan seem to be dying help

[kimmy06]

We did a water change yesterday for mantaince and added carbon to the filter media and some old food came rushing back up to the aquarium the Parameters are currently
salinity: 1.0
ph: 8.5
temperature: 79f
nitrate: 50 which was high so i think this is the problem now 25 after another water change
magnesium: 1200
calcium: 400

 

[NonstopSoda]

the calcium and magnesium are on the low side, how old is your tank? and how often do you do water changes

 

[kimmy06]

I have a 20 gallon long it’s been up and running for a year now we do a water change every two weeks or so

 

[kevgib67]

As @NonstopSoda mention you’ll need dose magnesium up 1350-1400 and calcium up 420-450. The consumption is exceeding the addition with biweekly water changes. Salinity: 1.0? Please post your phosphate.