Nitrates Refuse To Come Down

I've done 2 50% water changes, Nitrates are refusing to go down.

Current readings
.5 Ammonia
0 Nitrites
20-30 Nitrates

My initial readings before doing 2 50% changes were
.25 Ammonia
.5 Nitrites
30-40 Nitrates

Must add my tap reads
.5 Ammonia
0 Nitrites
0 Nitrates

 

How long after doing the water change do you test?

 

I tested about 6 hours after the first, those readings were
.5 Ammonia
.25 Nitrites
20-30 Nitrates

Current readings are immediately after

 

Let me get this straight.

Initial:
.25/.5/30-40

6 hours after 50% change:
.5/.25/20-30

Current readings:
.5/0/20-30

Looks like they came down to me! I think the ammonia in your tap water is what's making things difficult for you. I think you can estimate the final numbers by multiplying the ammonia reading by 4

 

Let me get this straight.

Initial:
.25/.5/30-40

6 hours after 50% change:
.5/.25/20-30

Current readings:
.5/0/20-30

Looks like they came down to me! I think the ammonia in your tap water is what's making things difficult for you. I think you can estimate the final numbers by multiplying the ammonia reading by 4

Nitrates, not Nitrites.

 

Nitrates are still going down if they were 30-40 ppm and they're now 20-30 ppm.

The ammonia is basically adding some nitrates (since the ammonia will be converted to nitrates), but with frequent and large water water changes, you can get nitrates down.

What size tank and what fish do you have in the tank? Your bioload may be too high.

 

Nitrates are still going down if they were 30-40 ppm and they're now 20-30 ppm.

The ammonia is basically adding some nitrates (since the ammonia will be converted to nitrates), but with frequent and large water water changes, you can get nitrates down.

What size tank and what fish do you have in the tank? Your bioload may be too high.

I've been doing 50% daily changes, but my bioload isn't too much for my tank. I'm currently stocked with 4 Molly, 6 Glo Tetras, 6 Corys in a 55 Gallon Tank. I'm experiencing a minI cycle due to switching to sand from gravel.

Shouldn't my Nitrates drop more with doing 2 50% changes within 6 hours?

 

Nitrates of up to 400ppm are not harmful to warm freshwater fish

 

That is a very broad and sweeping statement. I also hope you meant 40ppm; otherwise, this is the first I have ever heard this, and it doesn't sound right.

 

I'm giving estimates based on color. It's wasn't quite dark enough to be 40, but definitely darker than 20. The last 2 weren't dark enough for 40, but just darker than 20.

 

Nitrates, not Nitrites.

Yes...and it's clear from the numbers that the nitrAtes have dropped. Remember that the nitrates are always rising at some rate. Just the amount of ammonia in your tap water is adding significantly to the nitrates!

Your tap has .5ppm ammonia so that will be converted to approximately 2ppm nitrates and you're adding that every time you do a water change, on top of the wste produced by your fish!

 

So even once I finish this minI cycle, I can expect 20 ish ppm Nitrate to be "normal"?

 

Do you currently have live plants in there? I would add some or more to help in the long run.

 

Do you currently have live plants in there? I would add some or more to help in the long run.

I actually planned on adding some plants. This just gives me another reason to do so.

 

Oh yeah, 20-40 is perfectly normal! Maybe even a little low. If you have live plants you may even find that you need to supplement to keep them healthy

 

I don't see a problem with the nitrate levels...