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20g high low light plants not doing well

1854 Views 11 Replies 7 Participants Last post by  Surf
Hey all, I would appreciate some help with my planted tank. It has been established for about five weeks. Since then the plants have not been doing well.

The tank is a 20gallon high. The plants I have are java fern, amazon sword, cryptocoryne lucent, and an anachris. The only plant that is doing okay is the crptocoryne, yet it still is developing yellow/brownish spots. The java fern is black. The amazon sword leafs look thin and pale. The anachris is fine but it is a new addition. I previously had hornwort in the tank but that has since died.

For substrate I have caribsea eco-complete. For lighting I have the nicrew led and a 15w T8 TropicSun 5500k feature. The lights are on for a 12 hour period. I am also dosing Flourish Excel and aquavitro envy.

Any help would be greatly appreciated!
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Way too long of a photoperiod. You should have started around 6 hours then ramped up to ~8 hours over the course of about 6 weeks.

You are also barely giving them any nutrition, especially with a 12 hour photoperiod. Excel is a carbon supplement. Envy is kind of like a daily supplemental vitamin but without providing actual fertilization (micros and macros), they aren't supplementing anything. Look into the EI method of dosing and buy some dry ferts. $15 bucks will cover all nutrients and last a long time (probably more than a year) with a low light setup.

Eco complete is an inert substrate. It doesn't provide nutrients but it holds onto nutrients that you add (like root tabs or liquid/dry ferts).

Reduce your photoperiod, add some actual fertilization, and start doing weekly 50% water changes at a minimum. The current state of your tank is like running on a treadmill for 12 hours straight it the only nutrition you get is 2 slices of bread and a glass of water. Even the strongest of runners would eventually "die" if that's all they were given.

Light dictates everything a plant does and without a proper balance of light, nutrients, and co2 (gaseous co2, not excel, but excel can work very well in low tech setups not running pressurized co2) we run into issues.

Honestly, your tank could probably do without the led and just run the T8. Leds have the potential to produce very strong light (not always the case though). Don't underestimate the power of led. You could also try and run just the led. Either way, you have too much light for too long without providing your plants with enough nutrition to conpensate for the intense lighting. However, none of your plants need that amount of light so in return, they don't need much nutrients to begin with (which they take in slowly anyways).
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