Massive plant die off

[SupersoNick95]

Hello everyone, I’ve had this tank running for about a year now, and everything was fine until recently. 

I had explosive growth from my Java fern, crypts, and dwarf sag but it all died off about 2-3 months ago. My aquarium never really got near 10-20 ppm of nitrate but plants always grew well despite this. All of a sudden everything just stopped growing and turned brown. 

Oddly enough, the Anubias have seen explosive growth in the past couple of weeks. However, the new Java fern I added is already melting and so are the valisneria, despite adding a good amount to the coop easy tabs. Anything but Anubias or Swords seems to die off instantly once in the tank. 

do I just need more nitrates? What range of ppm should I be aiming for? I’m dosing quite a lot every week, almost double what the easy green bottle recommended for a high light aquarium and the nitrates never seem to rise past 20. Maybe it’s a lighting issue? I’m using a Fluval 3.0 with the light intensity somewhere at around 20% for about 5-6 hours a day. I’ve attached photos of my tank along with a water test and my fluval light settings.

[DaveO]

Looks like your kh and ph are very low. You might try adding a couple pounds of crushed coral to the substrate. Also your light is set kind of weak. Maybe bump it up to 30% at first, for a month or two to see if that helps. 40% might work well.  Also, duration could be increased to six or eight hours per day. Your plants growing well at first then hitting the wall, so to speak, could indicate a need for more fertilizer. 

[PlaneFishGuy]

On 1/19/2023 at 12:38 PM, SupersoNick95 said:

o I just need more nitrates? What range of ppm should I be aiming for?

I think most people shoot for 30-40 ppm in a planted tank. I believe that assumes regular water changes so you don't get a build up things you cant test for in the tank. 

I run my fluval 3.0 at about 30% and it sets about 15" above the substrate. I have no algae but my growth is fairly slow compared to when I ran a little higher. Id recommend the thread dedicated to the topic in the community resources section. I posted a spreadsheet a few years back that shows the various color percentages so you can dial up/down from the factory setting and keep the color ratios intact.  

[Patrick_G]

Your current plants look pretty good for a low tech tank. I find Java ferns can be tricky, in my low tech tanks they definitely show a cycle of strong growth followed buy a die off. They are potassium hogs so you might want to add some extra if you’re not already doing that. 

[nabokovfan87]

On 1/19/2023 at 10:38 AM, SupersoNick95 said:

I had explosive growth from my Java fern, crypts, and dwarf sag but it all died off about 2-3 months ago. My aquarium never really got near 10-20 ppm of nitrate but plants always grew well despite this. All of a sudden everything just stopped growing and turned brown. 

Definitely not an issue and means you control the nitrates via dosing.

What is your water change % volume and schedule?