nitrate 160ppm

[jaehyeokeom]

I am new to saltwater aquarium. It has been about a week since I had my 2 clownfish in Fluval 15gallons tank. I bought everything (heater, saltwater, clownfish, flakes, etc.) from my lfs store. I researched about clownfish and overall saltwater aquarium tips, because my lfs never explained any of this. I put sand ( I did not rinse or wash before I put it in tank) and the old salt water my lfs gave to me. Today I tested nitrate and it is blood red (over 160ppm) I read posts about the same circumstance like myself, and some reef masters tell him to do 100% water change, and keep testing the water quality.

Is it okay to do 100% water change? I have a little bit of ammonia (0-0.25) and nitrites (2.0-2.5) in my tank and PH level at 7.8-8.0 range. This is the first time testing them so I don’t know what the quality was like in the beginning.

I am just worried that doing a 100% water change might kill off some good bacteria and stuff and I don’t want to stress out my clownfish.

 

[KrisReef]

The question is how did the tank water get over 160ppm nitrates in only a couple of weeks?
If you are over feeding the fish that much then you need to drastically reduce the amount of food that you have been feeding them.
If you are using old sand or rock that has that much nitrate in it then you need to throughly clean the sand/ and or the rocks to remove the detritus that came with them.
If you used old water it might have had a lot of nitrates, replacing that water might solve the problem.
The difficulty of not knowing where the nitrates came from makes the course of action to resolve the problem difficult to pinpoint.

I think that a 50% water change a good place to start. Mix up a 5 gallon bucket of new salt water and test that water (should be close to zero) before you replace the old water.
Also, check your top off water ( also should be zero nitrates) to rule out that as a source of nitrates.
If your new water( mix and top off) is good then replace 5 gallons and measure the tank after a 5 gallon water change. The tank should be about 110 with five new gallons of low nitrate water. Wait a couple of days and measure again to see if the water is still around that 110 number. If it has gone back up towards the 160ppm number then the nitrates are either from over feeding or leaching out from the dirty gravel and rock.

Otherwise, the other source of error could be your test kit. Have the lfs test your water to rule out a bad test kit.

A 100% change with zero nitrate water should fix the issue but you need to be careful to match salinity, temperature, (and dkh if you have coral) to minimize stress to the critters in the tank when you do large water changes. The fish should be ok if you are only changing NO3 levels but coral don’t like zero nitrates (or zero phosphates) so going slow and doing a couple of 5 gallon replacements with new water is safer for a “reef” tank.
Hth.

 

[jaehyeokeom]

Wow well put! Thank you! My tank consists of only 2 clownfish (no reef or corals), so I might just go with 100 water change. Which do you personally think is better, small grain or bigger grain of live sand for clownfish?