New tank - high nitrates

[Audie]

I just set up a new tank 3 days ago with established sponges from another healthy tank. The only stock are a handful of rams horn snails and live plants. My nitrites are 0 but my nitrates are 100 or more. What is the reason for this and what can I do about it?

[FriendlyLoach]

I am not sure what could have caused it, maybe the test is wrong, liquid test kits are most accurate. Also something could be rotting that you don't see. I would do a 50% water change, test again and in a few days do more water changes as needed. 

[Dawn T]

I agree with the above recommendation. High nitrates are high bio load indicators - too much food, too high stocking, or something dead rotting in the tank. I've found that melting plants can increase nitrates some, too. How much depends on amount of melt and size of the tank, of course. That makes since given they're basically rotting. Snails SHOULD be taking care of that in your case, though.

That assumes, of course, that your test is accurate. I've found API's liquid test kit and Aquarium Coop test strips to be the most accurate. Others I've tried have varied greatly in reliability, so I stick with those 2.

Another thought - have you checked the nitrate levels in your tap water? Some municipalities have water that's already high in nitrates.

[Audie]

Thank you so much for your answers - I have tested my municipality’s water, it has 0 nitrates and nitrites and is fairly hard. As for the test strips, I use the same test strips on my other two tanks and don’t get the same result as my newly set-up tank referenced in my original question. 
 

A little history behind this new tank: I had a 5 gallon, heavily planted tank with snails and a couple of ghost shrimp. A few months into it my nitrates spiked really high and eventually killed my shrimp. I changed the water every other day, no food was going in and I removed any dead leaves immediately; but still my nitrates were high. After a year I took it apart, thoroughly washed the tank and equipment, added new gravel and added the same plants back in. This is now the tank where 3 days after doing this my nitrates are high again. Maybe it’s in the plants, since that’s the only factor that has remained the same? I don’t know, but I appreciate everyone’s suggestions. Thank you!

[Colu]

Are you using a nitrogen base liquid fertilizer such as easy green if  you are that could be cause of the high nitrates

[Audie]

Yes I am using easy green…. I didn’t know that could be the source of nitrates. What kind of fertilizers should I look for that won’t cause high nitrates? 

[Drenon88]

You probably don't need to switch brands but it sounds like you can/should cut back quite a bit on the dosing.

[Audie]

Thank you so much, very helpful. I didn’t think about fertilizers as a source. I will try this out!

[Colu]

I would stop dosing easy green till your nitrates drop below 20 ppm then I would dose at half the recommended dose of 1pump for 20 gallons instead of 1 pump for 10 gallons keep a close eye on your nitrates levels see were they are just before a water change you might have to lower or up your dosing of easy green depending where there end up