What are the challenges and limitations of "no fertilizer" planted tanks?

[Saint_abyssal]

I've heard a lot about people setting up aquaria to function as miniature ecosystems that can function with few artificial inputs like fertilizer. This naturalistic approach to fishkeeping appeals to me a lot more than relying on expensive products, frequent maintenance, and "artificial life support" more generally. That being said, I think most aquarists with planted tanks use some kind of chemical fertilizer rather than relying solely on their water chemistry and fish waste. That makes me concerned about whether or not the "natural" approach is sustainable or so limiting as to suck the fun out of the hobby.

So, in your opinion or experience what are the challenges and limitations of trying to run a planted aquarium without using chemical fertilizers?

 

[Magnum Man]

probably the biggest challenge is finding plants that will "thrive" with less ( what your fish are capable of producing, or the minerals included in your water changes )... I don't typically add fertilizer, but nearly all my plants are terrestrial plants growing out of the aquarium... but even then, some work better than others, with no added fertilizer... and there are some submerged plants that will do ok, without added fertilizer, but most require more nutrition, than what is naturally available

if you are leaning towards no water changes, be prepared for a barrage of replies advising for at least water changes
Welcome to the forum...

 

[GaryE]

I use almost no ferts. About every 6 months or so, I decide the Valls need a push and use a root tab or two. I only have Vallisneria americana in 2 or 3 of my tanks, and they've done well for years.

Plant choice is the only real issue. I use a lot of low light plants with unburied rhizomes - Bolbitis heudelotti, a couple of Anubias spp and java ferns. If you are patient and like the appearance of them, you can grow them in large numbers, and decorate a tank well with them.

I used to have large numbers of Cryptocoryne wendtii, which I lost in my move here. I have them restarted, and am starting to see the fert-free spread now.

I get excellent growth of Ludwigia repens and Bacopa if I let them reach above the surface as bog plants. Again, no ferts - just light stocking in my case with killifish, and clockwork level weekly water changing.

I've had java ferns reach almost 2 feet, with largely unblemished leaves.

When I see some of the planted wonders people post here - my tanks aren't in that league. Then again, I rarely have to trim, and the only expense is the higher cost of slower growing plants. I have no beef with ferts, and often intend to get some to see what they'd do. I just never get around to that. All my tanks are planted, but I'm a fish first aquarist, and I won't be winning any tank of the month contests.

 

[seangee]

No (or almost no) ferts for me. I bought inexpensive, easy plants and what thrived in my tanks stayed. Anything that struggled went in the bin. It really is a balance between light CO2, nutrients and possibly pH. Some plants thrive in one tank but not the others and others work in 2 or 3 (of 4) but not everywhere. And of course there are some that do well in all the tanks.

 

[10 Tanks]

Hello Saint. The whole plant thing for me is pretty simple. You stay with the easy to grow kind and there are a lot of them. With the easy plants, you can use inexpensive shop lighting. 6500K bulbs and watts in the 30 to 40 range per bulb will work well. A two to four bulb strip is easily available at the local Lowe's or Home Depot. High end fertilizers aren't needed, just make sure you feed your fish a variety of foods high in nitrogen, phosphate and potassium.

10

 

[gwand]

My tanks have Anubis, Amazon sword, Java fern and coryne wentii. I have never used fertilizer. My artificial light stays on for 6 hours per day. All the plants look great and most have been with me for 19 months.

 

[Saint_abyssal]

probably the biggest challenge is finding plants that will "thrive" with less ( what your fish are capable of producing, or the minerals included in your water changes )

I've attached a printout on my water chemistry and compiled a list of species of interest.

Surface floaters: Water lettuce (Pistia stratiotes) and red root floaters (Phyllanthus fluitans).

Background plants: Yellow Flame Bacopa (B. caroliniana), coontail (Ceratophyllum demersum), Elodea canadensis, and Leopard Vallisneria (V. spiralis).

Middle to back: Dark Red Ludwigia repens and red tiger lotus (Nymphaea zenkeri).

Midground: Lesser creeping rush (Juncus repens) and Pink Flamingo Cryptocoryne wendtii.

Fore-to-midground: A blue cultivar of Bucephalandra, Pink Cryptocoryne becketti petchii, and narrow-leaved arrowhead (Sagittaria subulata). Foreground: Banana lily (Nymphoides aquatica).

Would any of these species do okay under these conditions?

I don't typically add fertilizer, but nearly all my plants are terrestrial plants growing out of the aquarium... but even then, some work better than others, with no added fertilizer...

I'm also interested in emersed or hydroponically grown plants. Any recs?

if you are leaning towards no water changes, be prepared for a barrage of replies advising for at least water changes

Uh-oh. I definitely would prefer a no water change set up, but wouldn't be averse to doing so maybe a couple of times a year.

Welcome to the forum...

Thank! I appreciate the help you've given me.

 

[Magnum Man]

I'm not good enough with submerged plants to offer advice there, other than I've had very good luck with Java Fern, & almost no luck, with others I've tried...
As far as emersed or hydroponically grown... my best terrestrials, with no fertilizer... I grow out of hang on pots, with ceramic bio media which will host beneficial bacteria, & hold the plants in place, have been... in order of best to worst in my situation...

Pothos vines... Epipremnum Aureum
Chinese Evergreen... Aglaonema
Peace Lillies... Spathyphyllium
Hoya...
Lucky Bamboo...
Philodendron...

these are plants currently growing that I would recommend, if you were trying fertilizer free...
I have or have had growing Calathea, Nile Lily, & several water lilies & several other plants, that may grow, but did not thrive, without fertilizers...

I've tried nearly all the floating plants... & only had luck with Water Lettuce ( this one grows to well, & requires more maintenance to keep it from taking over, than I had time for ) I do grow Giant Duck weed, as I feed that to food grade Tilapia I raise... I would not do lemna minor, ( common Duckweed ) as it's too hard to contain... I currently have Water Hyacinth in 3 of my display tanks... it wants to take over as well, but has been about half the maintenance require of the water lettuce... I love frog bit, & Red Root Floaters, but I think I have too much water movement, for those plants to be happy, & they may require fertilizer to be happy...

I personally don't buy into any of the no water change systems... I use straight RO water right now, because my local water is rock hard, & using RO, & lots of mechanical filtration, & tons of plants, I try to do a 10 - 25% water change every 2 weeks... you'll find members here, that may not run any mechanical filtration, but rely only on water changes, but don't think you'll find any members on here, that don't do some water changes... with all my plants, I may extend my water changes out to 3 or even 4 weeks, if I get too busy, but would never go more than 4 weeks without a significant water change...,

 

[Saint_abyssal]

Plant choice is the only real issue.

I included a list of species of interest in my response to Magnum Man. I notice some overlaps between plants I want and the plants you've been growing. Do you think they would do well in my water chemistry? Any thoughts on any of the others?

No (or almost no) ferts for me. I bought inexpensive, easy plants and what thrived in my tanks stayed. Anything that struggled went in the bin. It really is a balance between light CO2, nutrients and possibly pH. Some plants thrive in one tank but not the others and others work in 2 or 3 (of 4) but not everywhere. And of course there are some that do well in all the tanks.

I like your "natural selection" based approach and may try something similar when I start setting up my tanks. I'm also very interested in what you think about my water chemistry and plants of interest list in my response to Magnum Man.

You stay with the easy to grow kind and there are a lot of them.

You're the third person I'm going to ask about the list of plants in my earlier response to Magnum Man. Are they good candidates?

With the easy plants, you can use inexpensive shop lighting. 6500K bulbs and watts in the 30 to 40 range per bulb will work well. A two to four bulb strip is easily available at the local Lowe's or Home Depot.

Awesome. I'm definitely interested in avoiding expensive specialty lighting.

High end fertilizers aren't needed, just make sure you feed your fish a variety of foods high in nitrogen, phosphate and potassium.

Any specific recommendations?

 

[GaryE]

I've attached a printout on my water chemistry and compiled a list of species of interest.
View attachment 343185

Surface floaters: Water lettuce (Pistia stratiotes) and red root floaters (Phyllanthus fluitans).

Background plants: Yellow Flame Bacopa (B. caroliniana), coontail (Ceratophyllum demersum), Elodea canadensis, and Leopard Vallisneria (V. spiralis).

Middle to back: Dark Red Ludwigia repens and red tiger lotus (Nymphaea zenkeri).

Midground: Lesser creeping rush (Juncus repens) and Pink Flamingo Cryptocoryne wendtii.

Fore-to-midground: A blue cultivar of Bucephalandra, Pink Cryptocoryne becketti petchii, and narrow-leaved arrowhead (Sagittaria subulata). Foreground: Banana lily (Nymphoides aquatica).

Would any of these species do okay under these conditions?


I'm also interested in emersed or hydroponically grown plants. Any recs?

Uh-oh. I definitely would prefer a no water change set up, but wouldn't be averse to doing so maybe a couple of times a year.

Thank! I appreciate the help you've given me.

There's a lot to unpack. First, no water change, or a couple of times a year means no fish. That's serious as a consideration. It also means mineral depletion won't be addressed. I still do weekly water changes in tanks that are 2/3 filled with excellent plant growth, with emergent bog plant roots in them. No water change tends to mean low minerals, and a competitive advantage for algae. Black beard algae loves no water changes, as does hair algae.
Pistia won't grow for me unless under a window, and then mainly in summer under direct sunlight. It has high lighting needs. In winter here, with strong plant leds, it still fades away.
Red root floaters are something I haven't tried. But "red" often says you need a good led plant light to make it work.
Bacopa emerges here, and flowers. It needs good light. Ceratophyllum and Elodea often decide they want to float. I've never been able to acclimate canadensis indoors. Vallisneria generally likes a few root tabs to start.
I have wild collected Ludwigia repens that is also emergent, and quite beautiful from above. Good light again. No shoplights there. Red tiger lotus also likes root tabs.
I've never tried Juncus. The local planted tank enthusiasts think I should, but then discuss the fert dosings I'd need. The Buce is out of my league. Crypt becketti with a starter root tab can usually pick it up with fish contributions, but grows better fed. The Sag can be started with tabs. The lily would be a great pond plant.

You're ambitious, but you are wandering into the land of trimming and fertilizers. Plus your choices need light. You like big plants and I cannot lie.

You can't have one of those competition winning tanks without a lot of work, lighting and ferts. I have Bolbitis, a few different Anubias, Crypt wendtii, Najas, java ferns and Valls. Above water, I have Lud. repens and Bac. caroliana. Those two do best in sunlight in a paludarium, though I recently moved some to tanks with good spectrum LEDs. So far, that experiment has worked, but I am not concerned with underwater foliage as these are shallower stream bank set ups. I like what I have, but I limit what I buy after killing a lot of plants over the past 50 years or so. My collection is 'distilled' down to basics.