Failing with plants


I've kept 20 gallon tanks for years and had wonderful success with plants. I've successfully grown Anachris, wisteria, amazon swords, java furn and frog bit. about 2 years ago I upgrade my 20 to a 30g tall and its become a plant execution chamber. I have a fluval aquasky 24-36 LED setup on top. I've experimented with light intensity settings around the 70-100% range. My attempts at CO2 have failed likely because I need to reseal all the connections with teflon. So it's been a low tech tank without CO2.

My water parameters are always 0 ammonia, 0 nitrite, 15 nitrate. phosphates undetectable. I've tried all the easy plants and everything last about 1-2 weeks before wilting and dying. I've tried all the easy stuff like anachris, wisteria, crypto, etc. All dead. Frogbit lingers but doesn't thrive (probably too high of flow). java fern and a micro sword have come the closest to living but they're really just been dying over a the last 2 years. Certainly not growing. Continuing slow deteriation.

I've had bad algae problems. I was good for maybe 6 months, then I had some nasty black algae that rode in on some plants. I've eliminated the black algae. I've cleaned out the sludge green algae, Now i'm just left with some light, bright green algae that covers the gravel ifI exceed weekly water changes. The current algae vaccuums up easy.

At first I thought it was the water depth. I thought maybe my aqua sky wasn't bright enough for the depth, but checking other peoples measurements of the same model I now think its actually too bright of a light for a low tech tank. I've lowered the light to 30% and turned off blue green and red (just white on).

I really haven't enjoyed this 30 gallon, I'm wondering if its just the worst of all worlds size wise. I would love to switch to a 55-75 gallon but I feel like I need to figure out the current issues before messing up a new tank. Any advice or specific light recommendations you've personally had success with on a 30 gallon low tech would be appreciated.

How do you fertilize your tank? Do you have root tabs/aquasoil/dirt? What about nutrients in the water column? Plants can't grow even with the brightest light if they don't have nutrients. Also undetectable phosphate may not actually be a good thing because plants need it to stay healthy, and deficiency leads to leaf deterioration and spot algae outbreaks.
  • Thread Starter
Historically I've experimented a bit but actually had the most success with easy plants that got enough off fish heavy tanks. With this tank, I started with tabs and copper-free, general liquid fert dosing (tank had shrimp at one point). after the first few plant die offs I reduced ferts because of the algae blooms. I also dug up and removed any remaining tabs. Substrate is inert. Currently there's no ferts, but was just clarifying I tried them last year in this tank.

With live fish I've never really needed ferts for anachris. It's always grown like a weed prior to this tank. Granted this 30 gallon tank also coincided with a move to a new water reservoir. Since I've tested phosphates and ammonia I'd guess there might be a difference in hardness or alkalinity. Tap pH is neutral and we have plenty of LFS on the same town water supply.
Fish waste mainly just provides nitrogen and phosphate. If that is all you're using to feed your plants, you're gambling your water supply has everything else in it the plants need--and the list is fairly long. My guess is you lucked out with your last water supply, but, now that you are in a new location, you'll need to feed your plants. I bet if you used dirt, aquasoil, and/or fertilizers, you'd see an improvement. Personally, I find most low tech tanks don't get enough potassium (amongst other things) without fertilization of some kind.

Your plants are stressed and dying. Stressed and dying plants feed algae. Fortunately, healthy plants combat algae. So, if you make your plants happy, you should have less algae (at least on them).

Also, tall tanks with less surface area will have even less available CO2 in a low tech tank than something shaped more like a 20 long. But, you said you had some current in there which should help mix the water up. If you add some surface agitation (if you haven't already), that should help your tank's gas exchange too.

Random Great Thread

Latest threads

Top Bottom