Plants NOT growing

[zdelellis]

Please help. I currently have a well established 10gallon, heavily planted tank with two rasboras, two otto’s, and one mystery snail as well as a 5 gallon tank with just shrimp. Both have fluval stratum capped with sand. My parameters are all within normal in both tanks with 0 ammonia/nitrites and ~15ppm nitrates. However in both tanks i’m struggling to grow my limnophila heterophylla and my wisteria. I dose Thrive S and potassium in both tanks twice a week. Lights are on about 8 hours a day but the algae seems to take over the plants before they can grow. I’ve adjusted adding more/reducing my ferts as well as increasing/decreasing the lights and nothing seems to work.

 

[ruud]

I note a couple of leaves that still have their terrestrial outfit; so the tank might be established, but the plants likely aren't.

Sometimes it takes a while before a plant settles and the growth hormones kick in. A month? Easily. I have similar experiences with Wisteria.

You can dose all the fertilizers you want, it won't matter.

My two suggestions; prevent algae in the first place. Light intensity plays a major role.
Secondly add, low CO2 tolerant plant species that are fine in lower light, like Limnophila sessiliflora, Rotala rotundifolia, Heteranthera zosterifolia, and of course Hemianthus glomeratus.

In this situation, sooner or later, plants will grow in the abscence of algae. Plant biomass increases. You can increase light intensity a little more. And add a little more difficult species.

 

[kansas]

There's a lot going on with water chemistry that most of us know nothing about. Some plants grow well in my water and some don't.

 

[zdelellis]

I note a couple of leaves that still have their terrestrial outfit; so the tank might be established, but the plants likely aren't.

Sometimes it takes a while before a plant settles and the growth hormones kick in. A month? Easily. I have similar experiences with Wisteria.

You can dose all the fertilizers you want, it won't matter.

My two suggestions; prevent algae in the first place. Light intensity plays a major role.
Secondly add, low CO2 tolerant plant species that are fine in lower light, like Limnophila sessiliflora, Rotala rotundifolia, Heteranthera zosterifolia, and of course Hemianthus glomeratus.

In this situation, sooner or later, plants will grow in the abscence of algae. Plant biomass increases. You can increase light intensity a little more. And add a little more difficult species.

Interesting and thank you for your help. The problem is that this tank has been running for ~7 months. The plants seem to do well sometimes but not other times. I was thinking there might not be enough organics as there are only a few waste producing fish. Is the solution to just get the algae under control and let it go?

 

[ruud]

Without a CO2 system, plants hardly need nutrients to begin with. Period.

Also, I'm not aware that an abundant concentration of nutrients in the environment acts as a physiological trigger.

Light intensity, temperature and gasses are much bigger factors. Nutrients are (mostly) a prerequisite.

People underestimate species differences. I have no experience with Limnophila heterophylla, but H. sessiliflora can also be very slow to kick-off and really grows fast under high light intensity.

But high light intensity is not what you want in the beginnings of a planted tank journey. Hence pick species that are also low CO2 tolerant, but easy to show growth quickly in low light.

And plant plenty from the start. Once the plants show steady growth and the total plant biomass increases, the 'degrees of freedom' increase and your tank and plants become more forgiving.

 

[zdelellis]

I note a couple of leaves that still have their terrestrial outfit; so the tank might be established, but the plants likely aren't.

Sometimes it takes a while before a plant settles and the growth hormones kick in. A month? Easily. I have similar experiences with Wisteria.

You can dose all the fertilizers you want, it won't matter.

My two suggestions; prevent algae in the first place. Light intensity plays a major role.
Secondly add, low CO2 tolerant plant species that are fine in lower light, like Limnophila sessiliflora, Rotala rotundifolia, Heteranthera zosterifolia, and of course Hemianthus glomeratus.

In this situation, sooner or later, plants will grow in the abscence of algae. Plant biomass increases. You can increase light intensity a little more. And add a little more difficult species.

Interesting and thank you for your help. The problem is that this tank has been running for

 

[Joshaeus]

I personally stink at growing submerged plants, so I have turned to using plastic plants underwater and floating plants and hydroponic houseplants above it. Floating plants - in theory - pretty much take care of themselves so long as (A) there is enough light, (B) the water isn't being agitated too much, and (C) the water is not too soft. With that being said, though, the only floating plants I consistently succeed with inside are water sprite, duckweed, and salvinia (water lettuce does great for me in my water gardens but is hit or miss indoors; I have not attempted water hyacinth indoors because of its size, but that plant has a reputation for doing badly indoors. Pity...).

Hydroponic houseplants require a little prep work, but after that are arguably even easier than floating plants; remove as much dirt/potting mix from the roots as you can, rinse the plant to remove any possible pesticides, then place the roots into the tank water and find some way to keep the plant there (a custom twin wall polycarbonate lid with holes for the plants, water proof spring clamps, plastic suction cup soap dishes...). For hydroponic houseplants your primary concern is providing enough light, which can easily be done with aquarium lights held above the tank or even BR-30 or 40 or PAR LED light bulbs situated above the plant with work lights(I'd stick to BR bulbs unless you are growing very light demanding plants, as PAR bulbs are quite focused and can easily burn lower light plants.). Three of my tanks use a custom wooden light stand with LED lights zip tied to it; it would not be hard to build such a stand or to have a friend build it, as it only requires a few pieces of 2 by 4's and doesn't need to hold a lot of weight. Soft water may hinder hydroponic houseplants but seldom causes them to fail outright in my experience. I've rarely had a hydroponic houseplant fail, the only exception being a thanksgiving cactus that literally fell apart when I tried growing it hydroponically (it was not in an aquarium but was rooted in a pot of leca with nutrient solution in a drainage tray at the bottom...with that said, though, you may want to be very cautious attempting to grow succulents hydroponically).

Of note is that terrestrial plants (houseplants!) and aquatic plants have differences in nutrient uptake preferences. Most aquatic plants prefer ammonia as their nitrogen source and will compete with the nitrifying bacteria/archaea for it if there is even a smidgen in the aquarium, often resulting in the aquatic plants ignoring the nitrates building up in the tank; most terrestrial plants, by contrast, prefer nitrate, which may make them a better choice for tanks that rely heavily on microbial filtration. Also, terrestrial and floating plants have access to far more CO2 than submerged plants and tend to grow considerably faster as a result (floating plants in particular can grow obscenely fast).

 

[DaveKS]

I’d likely look at circulation problems, not GPH but dead spots with little to no circulation.

Here’s my 2.5g.


I dose Thrive S at 1/3 label rate. Use a pitcher with 7cup water and 25drops Thrive. Then I use that to top off for evaporation 3x a week.

Drop the added K, you’re just throwing nutrient balance out of whack.

You want low, lean and consistent. Never to high but never any nutrient bottoming out to zero for any extended periods of time.

Red root floaters from above.

 

[zdelellis]

I’d likely look at circulation problems, not GPH but dead spots with little to no circulation.

Here’s my 2.5g.
View attachment 930508

I dose Thrive S at 1/3 label rate. Use a pitcher with 7cup water and 25drops Thrive. Then I use that to top off for evaporation 3x a week.

Drop the added K, you’re just throwing nutrient balance out of whack.

You want low, lean and consistent. Never to high but never any nutrient bottoming out to zero for any extended periods of time.

Red root floaters from above.

View attachment 930509

Interesting, both of those plants are planted in a low circulation area. Could that really be the cause of algae taking over so fast? Should I move my filter to the (width) edge of the tank to to flows over the entire length of it?

 

[DaveKS]

Interesting, both of those plants are planted in a low circulation area. Could that really be the cause of algae taking over so fast? Should I move my filter to the (width) edge of the tank to to flows over the entire length of it?

Yes, anything you can do to get water moving around tank in a circular motion will help.

 

[TClare]

Floating plants - in theory - pretty much take care of themselves so long as (A) there is enough light, (B) the water isn't being agitated too much, and (C) the water is not too soft. With that being said, though, the only floating plants I consistently succeed with inside are water sprite, duckweed, and salvinia (water lettuce does great for me in my water gardens but is hit or miss indoors; I have not attempted water hyacinth indoors because of its size, but that plant has a reputation for doing badly indoors. Pity...).

I have to disagree with C. I have very soft water and floating plants do just fine - water lettuce and frogbit, I haven’t tried any others. After all they come from the Amazon region with soft water..water lettuce doesn’t survive long outside here, it’s too cold especially at night.

I did keep some water hyacinths in an indoor tank for a while, I really put them in as they had been in a tub outside and the roots had some scuds in that I wanted to feed to the pike cichlids. They did survive for several months, but got a bit too big really. I tried one in my big tank but it was eaten.