High Nitrates In 2 Of My Tanks

I did my usual weekly water changes yesterday and tested my tanks today just to check in that things are going ok. Surprisingly 2 out of 3 of my tanks are showing nitrates at 40-80ppm! I did another partial water change on the tank showing 80ppm, that got the nitrate level down to 40 but I'm wondering how the two tanks are showing such high nitrates? My third tank is showing 20ppm.

I'm using the API Master test kit. The tank at 80 has been set up for a couple of years and houses a single betta with live plants, the one at 40 has been set up for a few weeks but was seeded from a mature tank, it contains 8 WCMM with live plants, and the one at 20 has been set up for 4 years (also home to a Betta and live plants). My tap water shows 0 nitrates.

 

I did my usual weekly water changes yesterday and tested my tanks today just to check in that things are going ok. Surprisingly 2 out of 3 of my tanks are showing nitrates at 40-80ppm! I did another partial water change on the tank showing 80ppm, that got the nitrate level down to 40 but I'm wondering how the two tanks are showing such high nitrates? My third tank is showing 20ppm.

I'm using the API Master test kit. The tank at 80 has been set up for a couple of years and houses a single betta with live plants, the one at 40 has been set up for a few weeks but was seeded from a mature tank, it contains 8 WCMM with live plants, and the one at 20 has been set up for 4 years (also home to a Betta and live plants). My tap water shows 0 nitrates.

When you do your water changes are you doing a full gravel syphon?

When was the last time you cleaned your filter?

How stocked are the tanks?

How often are you feeding?

 

I do a full gravel siphon every second water change.

Tank 1 (nitrate 80ppm): 9 gallon tank, I am running 2 sponge filters and swish them in old tank water once a month. This tank has 1 Betta, 2 amazon swords, 2 crypts and an anubias.

Tank 2 (40ppm): 17.9 gallon tank, running a Hagen Elite Hush 25, I swish the filter media in old tank water once a month. Occupants are 8 white cloud mountain minnows, a few red cherry shrimp, some snails, 1 amazon sword, 1 crypt and some elodea.

Tank 3 (20ppm): 9 gallon tank, the same as my other tank except has more crypts and java moss rather than anubias. Home to 1 betta and several red cherry shrimp.

I feed both betta tanks twice a day. The betta get 2-3 pellets each time. The shrimp get thrown an algae wafer, some flakes or some balanched peas every 2 days. I also feed the WCMM twice a day, usually a pinch of small fish pellets, or some blanched peas. Once a week I replace one feeding in all tanks with some frozen bloodworms and a I try to skip one feeding a week if I remember.

 

I do a full gravel siphon every second water change.

Tank 1 (nitrate 80ppm): 9 gallon tank, I am running 2 sponge filters and swish them in old tank water once a month. This tank has 1 Betta, 2 amazon swords, 2 crypts and an anubias.

Tank 2 (40ppm): 17.9 gallon tank, running a Hagen Elite Hush 25, I swish the filter media in old tank water once a month. Occupants are 8 white cloud mountain minnows, a few red cherry shrimp, some snails, 1 amazon sword, 1 crypt and some elodea.

Tank 3 (20ppm): 9 gallon tank, the same as my other tank except has more crypts and java moss rather than anubias. Home to 1 betta and several red cherry shrimp.

I feed both betta tanks twice a day. The betta get 2-3 pellets each time. The shrimp get thrown an algae wafer, some flakes or some balanched peas every 2 days. I also feed the WCMM twice a day, usually a pinch of small fish pellets, or some blanched peas. Once a week I replace one feeding in all tanks with some frozen bloodworms and a I try to skip one feeding a week if I remember.

I would up the gravel syphon to every change to see if that helps. The bio loads in your ranks are pretty low so I would say you bb isn't fully developed.

When you clean your sponges are you alternating what one you clean every week?

I would do a few water changes to lower the levels and just keep monitoring the levels. Cut the feeding back a bit and see if the levels even out. Adding some cycle liquid may help out as well.

 

Yeah I usually alternate cleaning the sponges.

The fish all seem perfectly happy, active and eating. I think I'll cut the feeding to once a day and maybe do another water change mid week.

 

Have you checked your tap water? Sometimes your tap water values will change. If you have ammonia in your tap it will up your nitrates.

I would do a 75% water change to get those nitrates down as close to 5 as you can. Since it is rising so quickly.

Are you using fertilizers for your plants?

 

I haven't checked the tap water for ammonia, I'll do that after work. I use Seachem Excel and some root tabs for my plants