Help with growing floating plants successfully

[KaitieG]

I've tried different floating plants in my tanks:

-Duckweed (large and regular (twice)) turns white and dies

-Frogbit--melts and disappears

-Salvinia--melts and disappears

-Water Sprite--down to about 1/3 of what I added 6 weeks ago--turning brown and falling apart

Hornwort--this one might have worked, but it dropped needles and clogged up my siphon so much that it drove me NUTS and I removed it.

I've tried free-floating and having feeding rings around the HOB filter output and having rings around the floating plants--none of those have fixed the issues.

I have very hard water (LFS made a guess that this might be the issue) and a cover on the tank with just the LEDs that came with the kit, not plant lights.  I'm wondering if they don't get enough airflow and/or if the light is insufficient.  Nitrates are always between 20 and 40.   My anubias grow great--slowly, but very nice looking.  Java fern is decent. 

I love the look of floating plants and I could use the help with nitrates.  I really want to be able to grow something--any ideas what I'm doing wrong?  

I'd really appreciate any suggestions!

[Brandy]

If you have a cover on the tank that can be a problem. I have better luck with low flow and no cover, bright light, and I have also noticed some did better in the summer, so warmer tanks may also help.

[KaitieG]

So, I love the looks of tanks without covers and would love to try that out.  Here's my concern, but maybe this belongs in a different section--with very hard water, would the increased evaporation end up just perpetually making my already hard water even harder over time?  As I understand it, the minerals in the water don't evaporate, so do I need to be topping off then with RO or distilled water to keep things stable (it really doesn't need any help being harder!).

 

[Brandy]

49 minutes ago, KaitieG said:

So, I love the looks of tanks without covers and would love to try that out.  Here's my concern, but maybe this belongs in a different section--with very hard water, would the increased evaporation end up just perpetually making my already hard water even harder over time?  As I understand it, the minerals in the water don't evaporate, so do I need to be topping off then with RO or distilled water to keep things stable (it really doesn't need any help being harder!).

 

That is correct, and a valid concern. 

[Irene]

I found that too much flow was my issue. I was using a sponge filter with a stronger air pump in a 5-gallon betta tank, but had to switch to the gentler USB nano air pump. Afterwards, the Amazon frogbit and red root floaters did great, despite the presence of an aquarium lid.

 

[KaitieG]

28 minutes ago, Irene said:

I found that too much flow was my issue. I was using a sponge filter with a stronger air pump in a 5-gallon betta tank, but had to switch to the gentler USB nano air pump. Afterwards, the Amazon frogbit and red root floaters did great, despite the presence of an aquarium lid.

 

I have a sponge and a HOB--the flow could be an issue as I usually stick the floating plant ring over the sponge filter because it's farther from the HOB, which creates quite a strong flow.  I'm leaning towards trying an undergravel and sponge setup in the new tank, so I'll see how it goes with that.  Good to know it's possible to use with lids.  Thank you!

[gardenman]

Lighting and water flow would be the two most likely culprits. Floating plants are among the most reliable growers for me in my tanks. I've got duckweed, water sprite, frogbit, red root floaters, salvinia minima (water spangles), and dwarf water lettuce all growing well in nearly every tank right now. A couple of my more brightly lit tanks have some water hyacinths from my backyard water garden that I'm carrying over inside and they're doing well. Hard water can be hard in  couple of different ways. I have insanely high iron hardness (good for plants) but very low calcium hardness. Your water could be very hard, but hard in terms of calcium hardness and not iron and the iron deficiency could be an issue. An easy way to defeat too much water motion is to simply float a bowl in your tank and put some floating plants in that bowl. The bowl will move around in the current, but the plants inside the bowl won't be affected. If the plants in the bowl don't do well, then you can assume it's the lighting or something in the water and not the water movement. Once you figure out the problem your big issue will be: "What do I do with all of these floating plants?" They become very prolific, very quickly. One thing you don't have to worry about with floating plants is CO2. They get that more from the air than the water column.

[KaitieG]

In all honesty I focused a lot more on learning about keeping fish happy than keeping aquatic plants happy.  The Anubias did fine so I figured things should be okay for floating plants too.  That being said, I've realized my lighting really isn't good (despite the anubias) and I'm probably missing trace nutrients and/or they're tied up because I do have very high calcium hardness.  I found a good sale on glass lids and actual plant lights (yeah--probably should have started there a while ago!) and will be updating to those whenever they get here.  And then I looked around and found what sounds like a decent trace mineral only fertilizer--I have plenty of nitrate so I don't really want to add more of that at this point I don't think.  I'll let you know what happens after I've changed those things for a few weeks!  I'll have to figure out how to get my hands on a few more floating plants in the middle of winter, too, to test out the new system!  The LFS doesn't sell any of them.

[Pearl]

I think your instincts were right, in my experience most floater plants aren't that sensitive to water quality, so if the anubias is surviving just fine I would think floaters would be okay too. I would bet flow and light are your bigger problems here. Personally, I've never had success with floaters in a high flow tank. I have a tank that is arguably perfect for floaters besides the high surface agitation. The parameters are good, the lights are strong and yet duckweed and every other floater still dies or refuses to grow in that tank.
If high flow is a problem in my tanks with a HOB I usually put a square of coarse sponge in front of the output/overflow bit (I'm forgetting the proper term) to diffuse the water. Sometimes it can be tricky to get the sponge to stay, so what I usually do is cut a large piece that easily "blocks" the overflow, notch the sponge about a cm down from each corner with a razor blade, and with 100% polyester thread (natural fibers will rot away quickly) loop the thread around the hob once and sponge twice, in a sort of figure 8 while making sure the thread is in the notches. Then tape down the thread to the sides of the HOB if it doesn't feel secure enough. Not the prettiest but It works!

I think lighting will help with growth for sure, though I think you will have much more success if you reduce the water flow as well!  

[Maggie]

I have regular LED lights and glass lids, and 2 of my floating plants (sprite and salvinia minima) took over so much, I had enough for 2 bunches of throw aways for the quarantine tank, enough for the top of another tank (itself also taking over), plus had to donate alot and throw some out, after just a couple months. I have very soft water but use a little crushed coral in the danio tank to keep it at ~7.5; rasbora tank is at ~6.7. My other plants in the rasbora tank have suffered. The hornwort lost all its needles except at the very top and made a huge mess of needles so I got rid of it - I feel your pain there. I lost a bunch of other plants I don't even know the name of (bought "beginner package" from somewhere and nothing was labeled). The salvinia does not like getting thrown around in the filter flow at all, so I ordered some barriers. Good luck with your plants!

[KaitieG]

On 12/24/2020 at 2:58 PM, Pearl said:

If high flow is a problem in my tanks with a HOB I usually put a square of coarse sponge in front of the output/overflow bit (I'm forgetting the proper term) to diffuse the water. Sometimes it can be tricky to get the sponge to stay, so what I usually do is cut a large piece that easily "blocks" the overflow, notch the sponge about a cm down from each corner with a razor blade, and with 100% polyester thread (natural fibers will rot away quickly) loop the thread around the hob once and sponge twice, in a sort of figure 8 while making sure the thread is in the notches. Then tape down the thread to the sides of the HOB if it doesn't feel secure enough. Not the prettiest but It works!

I think lighting will help with growth for sure, though I think you will have much more success if you reduce the water flow as well!  

Thanks!  This will be my project tomorrow--it's time for a water change anyway, so I'll mess around with it then and see what I can rig up!  I have a pre-filter sponge on, but it never occurred to me to try a POST-filter sponge 🙂 

[Pearl]

Hope it works out (worked out?) for you! Let me know if you need any ideas on how to rig it if its causing you trouble.  It can be a bit tricky to get the post-filter sponge to stay on some of the weirder shaped HOBs.

[Tanked]

One of my first plants was Water Sprite.  It was supposed to be a bulletproof low light plant, but eventually died off.  Next I added Hornwort, Anacharis, and a stronger light.. 

I've found HW to be finicky.  Sometimes it grows for me and sometimes it doesn't.  Mine actually tumbled in the output from the HOB with no problems.  The Anacharis did not do well until it made it to the surface (closer to the light) where it thrived, eventually putting down long roots into the water column.  The HW got less light and was no longer in a strong flow. It became an algae farm.

I would try adding supplemental light first. Something as simple as an led lamp next to the tank might work.   If you see a change for the better, you can proceed from there..

 

[Mridul Singh]

I can make a few guesses as to what you might need to fix:

Seeing that the floaters turn white and die, it's probably need of more nitrates, or light. You mentioned that you have ~20-40 ppm Nitrates, so that should be fine, unless there isn't enough light to allow for the plants to grab them up from the water column.

I'd also remove the cover, and to work around your hard water, try adding either RO water as a top off, or if there's not too much evaporation, let it be.

Reducing flow can also help, as they like to be still at the top.

Hope that helps.

[KaitieG]

17 minutes ago, Mridul Singh said:

 

Seeing that the floaters turn white and die, it's probably need of more nitrates, or light. You mentioned that you have ~20-40 ppm Nitrates, so that should be fine, unless there isn't enough light to allow for the plants to grab them up from the water column.

Thanks--I really appreciate eveyone's help!

Here are the changes I've put in place that should make all the plants happier:

-Updated to glass lids as I found a good sale (and promptly got to buy a third since I was unaware that I was leaning on one of them as I fiddled with getting the cords arranged behind the tank...guess that's the downside of glass!). 

-Replaced kit lights with (budget Nicrew) plant LEDs.  The new big tank will probably get fancy lights, but I wasn't going to get the okay for that piece of the budget for the current tanks.

-Also after reading @Pearl's suggestion with reducing flow and watching @Irene's video on some of the options, I have a couple little suction cup soap dishes coming and will try those out with marbles to see if that works--if not, I'll fiddle with the sponge, but this sounded a lot easier (and potentially more attractive)  

-Found a micro nutrients only fertilizer and will start with that whenever it gets here.  Since I'd like to lower my nitrate anyway (hence the floating plants--well, I like the aesthetics too) it didn't make lots of sense to me to be adding it in.  So, I'll let you know how it goes!

So far, I like the glass lids (other than the whole breakable part--good thing it was me and not the kids!) and the "moonlight" setting with the blue LEDs makes the kids' rainbow gravel really glow, so they're fans of the new lighting,  We'll see what the plants think!

I currently only have (barely alive) floating water sprite, but if everything else takes off, I'll try to get some other floaters.  Shipping those in can be tricky in the winter temps here and my LFS doesn't sell them.

[FishyThoughts]

Since your upgrading the light you may need to watch your anubias. They can tend to grow algae if there’s too much light on them which can cause problems for them getting nutrients. The Java fern will probably do a little better with the better light. 
As for my experience, the many issue with floating plants definitely seems to be flow. I had some for awhile that were doing good when I had the flow limited. But with the tank they were in the limited flow was causing other problems, so increased flow and they started dying. And it’s fairly hard water here, so I’d assume they should do well in hard water for you as well. 

[O13SC3N3]

When they take off you won't know what to do with them... Every week I can fill a 30 gallon trash bag with them... And that's just 2 10 gallon betta tanks... 1 heavily planted, with a decent light. And the other one has fake decor, and standard let light that came with it, and the Frogbit grows just as fast... It's butts. I can remove all the parents. Leave the baby, and in a week or two at most they are growing over the edge, roots reaching well past a foot. The Bettas love it. And our largest golden Mystery is nicknamed Tarzan cause he (is male) swings across the tank by roots. 😅