Low Nitrates

Runnin'Reefer · Jan 18, 2023

Hello! I'm using an API test to test my nitrates. They are sitting in between 0 ppm and 5 ppm and I have used my two different kits. I just got some carbon to put in my tank to try to get rid of phosphate because I had a big algae outbreak. The algae has been steadily going down thanks in part to that and my tailspot blenny. I am leaving my tank for 2 weeks and my dad is taking care of it for me. I was going to do a water change tonight and add the carbon. I haven't done a water change in weeks. All my parameters are good. I'm worried if I do a water change and add the carbon it will drop my nitrates to 0. I have a pretty big skimmer running, so I'm wondering if a lot of the excess food isn't breaking down and turning into nitrates. Would it be a good idea to run my skimmer only half the day. I'm open to suggestions. When I get back in 2 weeks I might start dosing nitrates. Thanks in advance!

DanyL · Jan 19, 2023

It sounds like a new system, please share a bit more - age, kind of rocks, livestock, parameters.

Generally speaking, while carbon may bind some of your phosphates it'll be a negligible difference, it is mostly used to pull toxins and make your water clearer.

How much phosphates did you have?
Was there any real reason to lower them other than to chase a certain number?

Dosing nitrates is completely fine, however I'll not do so if there is no real need.
That being said, if lowering phosphates is a goal - increasing your nitrates may help decreasing phosphates by consumption.

As a big advocate of water changes, I advice to keep doing them routinely.
If depleting nutrients is a problem I would take care of it individually.

Randy Holmes-Farley · Jan 19, 2023

Runnin'Reefer said:
Hello! I'm using an API test to test my nitrates. They are sitting in between 0 ppm and 5 ppm and I have used my two different kits. I just got some carbon to put in my tank to try to get rid of phosphate because I had a big algae outbreak. The algae has been steadily going down thanks in part to that and my tailspot blenny. I am leaving my tank for 2 weeks and my dad is taking care of it for me. I was going to do a water change tonight and add the carbon. I haven't done a water change in weeks. All my parameters are good. I'm worried if I do a water change and add the carbon it will drop my nitrates to 0. I have a pretty big skimmer running, so I'm wondering if a lot of the excess food isn't breaking down and turning into nitrates. Would it be a good idea to run my skimmer only half the day. I'm open to suggestions. When I get back in 2 weeks I might start dosing nitrates. Thanks in advance!

If you mean activated carbon, it is unlikely to have a noticeable impact on nitrate or phosphate or algae.