why won't plants grow in my 21 inch deep tank

[David D]

Spoiler

 

Why can't I grow plants in my 21/24 inch deep aquariums, previously I had a 120 gallon 5' tank, 24 inches deep, I couldn't get any plants to grow in it besides Anubis and Java fern, any stem plants will eventually rot off at the gravel. Substrate is dime and smaller gravel. Light is a 48 inch nicrew, suspended about 5 inches above the tanks. My new tank is a 130 gallon waterbox, this time I added additional free standing grow lights, and the anubius looks like the leaves are burnt, suddenly turned brown, too bright of lights i'm guessing. at 21 inches deep, with fluval stratum under the same gravel, ordered pogostemus octo, water sprite and Brazillan penny wort, added root tabs to the pots, put the pots into the gravel, been a few weeks, the  penny wort has rotted off, the water sprite is not looking good, losing sections every few days, pogostemus hanging in there. Do I have too much light or not enough? No ammonia or nitrites, nitrates are at about 50 ppm, use easy green once a week also. Anyone have any suggestions?? sorry but the photo downloads upside down, even if I rotate it

[jwcarlson]

If you figure it out, let me know.  I had a beautiful pogo that basically poofed overnight and I can't get anything to grow much except dwarf water lettuce.  Anubias looks good in mine and growing faster than anything else (make no sense).   The stem plants seem to do really well for 2-3 weeks and then - gone.  Have tried pumping lots of easy green to it and it doesn't seem to really help.  So I've kind of adopted a survival of the fittest regiment.  If it lives, great, if it dies... OK.

Kinda stinks.  I'm cutting back on the water lettuce to see if it's just slurping up too much light and nutrients.  It doesn't look like much is stocked in your tank for fish.  I have had better luck letting sprite float and someone told me it is better for them if they glue or tie it off like anubias.

Good luck!

Edited November 24, 2022 by jwcarlson

[David D]

The photo was taken before the plant shipment arrived, I'm having the same issues with plants only living a few weeks, then dead... hoping someone here may have an idea or suggestion

[Fish Folk]

Upside down thing was triggering me. Here you go...

Hard as this may be to believe . . . I think that you light is not able to put out enough to really penetrate to that depth and grow stem plants adequately. It is fine for low light level plants, button sufficient for most others. If it were over a 33 gal long, it might do just fine. I think. you'll need to invest in a light with maybe 60 watts . . . you'll need to invest ca. $250+

This seems ludicrous when you're looking at all the light this one puts off. But there is a reality of "you get what you pay for" with aquarium lighting.

Edited November 24, 2022 by Fish Folk

[David D]

Thank you Fish Folk!

[NOLANANO]

Its because you are growing them upside down.  try flipping it over like Fish Folk suggested. lol.

Is that a Hygger light? I have one on my 75G which is 21" deep and it grows plants really well but what works for one person may not for another.  Before investing in an expensive light, have you tried root tabs?

[David D]

it is a nicrew light, yes i'm using root tabs, and this time I have two big bags of fluval stratum under the gravel

 

[Seattle_Aquarist]

Hi @David D

You didn't state if you which Nicrew model you had (Full Spectrum or White/Blue) or the specific size 36"-48" or the 48" - xx" (it makes a difference) but even if it is the 48"-xx" I agree with Fish Folks the issue is insufficient light.  How insufficient?  Either model only does a maximum of PAR@70-75 at 12" distance in open air....less through water and even further reduced if there is a glass top.

I use the Fluval 3.0 on my 75 gallon which is 21" high and 18" front to back.  The PAR level at 12" in open air is 136.  My light sits directly on the tank rim.  In my 75 gallon I measured the PAR level with an Apogee MQ-510 PAR meter at PAR@73 +/- 5 at the substrate level through a clean glass top.  This equates to 'medium-high' light.  The light level was remarkably even front to back and side to side.  With PAR@73 and CO2 I can grow most plant species including foreground carpeting species.  75 gallon photos below. Hope this helps! -Roy

 

Edited November 25, 2022 by Seattle_Aquarist

[Cory]

Having the light raised up above the tank, is costing you probably near half your overall light output. A light the length of your tank, resting on the rim, and that is powerful enough will solve a lot of the hassle you've got currently.

[nabokovfan87]

On 11/25/2022 at 11:34 AM, Cory said:

Having the light raised up above the tank, is costing you probably near half your overall light output. A light the length of your tank, resting on the rim, and that is powerful enough will solve a lot of the hassle you've got currently.

100%.  It's about refraction and non-direct light.  Because you don't have a lid, that's a good thing here in terms of refraction. Having the light with a short length as well as determining the angle of the LED also plays another big role here. 

Considering the tang size and length I think you would do better with two lights in this scenario.

Right now I would turn the light you have up higher to see if you can get enough light penetration.  These plants marked I would dose with root tabs. I don't know if everything else is anubias or swords in the pots, but swords you would also dose with root tabs.





These sections of the tank I would consider no or low light sections.  You can see on the anubias that the wood is casting shadows.  Similar to the rocks on the right.  Some of the plants in those areas should be placed elsewhere to give them a better chance at light.  Where you have those blue lines on the tank I would have one light for each half of the tank.  You can still have them mounted and looking awesome, but it gives you a lot better coverage of the tank.

 

On 11/23/2022 at 4:53 PM, jwcarlson said:

I had a beautiful pogo that basically poofed overnight and I can't get anything to grow much except dwarf water lettuce.  Anubias looks good in mine and growing faster than anything else (make no sense).   The stem plants seem to do really well for 2-3 weeks and then - gone. 

On the stems, make sure you're using root tabs.  as far as other things going on:

A.  Plants arrive and slowly die off because of nutrient and/or lighting issues. Stems especially are light hogs and will wither away if there's KH, PH, or nutrient issues in addition to lighting issues.  (Happens all the time with me with Scarlet Temple)

B.  Anubias is a shade friendly plant.  It doesn't need a lot of light.  It's probably clean of algae and the placement is such that you have adequate lighting for that plant to do well.  Usually anubias can do well with liquid ferts (but often just fish load).

C.  I don't know the full details of the setup, but I imagine the discussion above is also what's going on.

Let me give you an example directly related to my own experiences in my tank.  29G, which does need a decent light to reach plants at the bottom of the tank.  I'll fully admit this tank was not in great shape, but let's focus on lighting right now.

You can see DHG and S. Repens in the front corners (no hardscape blocking) and they all generally look dead.  This light was a 24" light cranked to 75-85% (going higher meant severe algae growth).



Replacing this with a longer light means that the LEDs cover to the edges of the tank better. The actual LED strip is longer. 20" vs. 30" LED strip and the light itself has 33% more LEDs.  Not saying it would be a perfect scenario, but it does "cover" better.



If you focus on the shadows on the substrate you can see the difference. The shorter, less powerful like does cast more, darker shadows.  For some plants this is the difference between growth and between withering away.

As far as what specifically is going on with your tank. I would suggest posting in the plant section with details, Test parameters, and a bit of explanation on your care for the plants.  There are some insanely talented plant people on the forums.  Many of them will be able to concisely help get things going for you.

This is that same tank now.   You can see the S. Repens doing much better.

[dmurray407]

On 11/25/2022 at 1:34 PM, Cory said:

Having the light raised up above the tank, is costing you probably near half your overall light output. A light the length of your tank, resting on the rim, and that is powerful enough will solve a lot of the hassle you've got currently.

Thank you for this, Cory!  I have a Fluval 3.0 light that I raised 6.5 inches above the rim of my tank (24 inches tall) to accommodate some plants I have growing on the back of my tank. My aquarium plants tend to struggle but I kept thinking-"I have this great light, the amount of light should be fine". I didn't realize the height would make that much difference. I'll be dropping the light back down in the morning-the Pothos on the back should still be fine. I like to keep the Pothos happy because they do eat a lot of nitrate, but they are technically a low light plant.

[SandSea]

i had this issue, my fix=

1) buy a rectangular shaped woven plastic basket from dollar store.

2)buy the large prewashed salad from the grocery store.

3) plant your plants in the salad container after you eat the salad

4) put the planted salad container on top of the plastic basket, it is now tall enough for the lighting. I also added in the substrate Seachem Flourish Tabs Growth Supplement - Aquatic Plant Stimulant, and lightly dosed the water column with Aquariumcoop easy green, i dont plant the whole tank, so i never know how much to add.

my plants now grow so well in all my tanks i actually have to trim the tops off every so often

Edited November 26, 2022 by SandSea

[SandSea]

On 11/25/2022 at 12:11 PM, Seattle_Aquarist said:

Hi @David D

You didn't state if you which Nicrew model you had (Full Spectrum or White/Blue) or the specific size 36"-48" or the 48" - xx" (it makes a difference) but even if it is the 48"-xx" I agree with Fish Folks the issue is insufficient light.  How insufficient?  Either model only does a maximum of PAR@70-75 at 12" distance in open air....less through water and even further reduced if there is a glass top.

I use the Fluval 3.0 on my 75 gallon which is 21" high and 18" front to back.  The PAR level at 12" in open air is 136.  My light sits directly on the tank rim.  In my 75 gallon I measured the PAR level with an Apogee MQ-510 PAR meter at PAR@73 +/- 5 at the substrate level through a clean glass top.  This equates to 'medium-high' light.  The light level was remarkably even front to back and side to side.  With PAR@73 and CO2 I can grow most plant species including foreground carpeting species.  75 gallon photos below. Hope this helps! -Roy

 

omg that’s great info, thank you. Knowing this, I might just plant more in my tallest tank, Most of us do not have a PAR meter. So your tank is 48 inches long, what size (length) of the Fluval 3.0 did you get? I wonder if the PAR is just as good with the shorter lamps

On 11/25/2022 at 12:11 PM, Seattle_Aquarist said:

 

Edited November 26, 2022 by SandSea

[Seattle_Aquarist]

On 11/26/2022 at 1:00 PM, SandSea said:

omg that’s great info, thank you. Knowing this, I might just plant more in my tallest tank, Most of us do not have a PAR meter. So your tank is 48 inches long, what size (length) of the Fluval 3.0 did you get? I wonder if the PAR is just as good with the shorter lamps

Hi @SandSea

I got the Fluval Plant 3.0 that is 48" - 60" long, 59 watt.  It is likely that directly under the light the PAR level would be equivalent, however there would be drop off at both sides and the four corners. -Roy

[jwcarlson]

On 11/25/2022 at 3:37 PM, nabokovfan87 said:

On the stems, make sure you're using root tabs.  as far as other things going on:

A.  Plants arrive and slowly die off because of nutrient and/or lighting issues. Stems especially are light hogs and will wither away if there's KH, PH, or nutrient issues in addition to lighting issues.  (Happens all the time with me with Scarlet Temple)

B.  Anubias is a shade friendly plant.  It doesn't need a lot of light.  It's probably clean of algae and the placement is such that you have adequate lighting for that plant to do well.  Usually anubias can do well with liquid ferts (but often just fish load).

C.  I don't know the full details of the setup, but I imagine the discussion above is also what's going on.

Let me give you an example directly related to my own experiences in my tank.  29G, which does need a decent light to reach plants at the bottom of the tank.  I'll fully admit this tank was not in great shape, but let's focus on lighting right now.

You can see DHG and S. Repens in the front corners (no hardscape blocking) and they all generally look dead.  This light was a 24" light cranked to 75-85% (going higher meant severe algae growth).

Replacing this with a longer light means that the LEDs cover to the edges of the tank better. The actual LED strip is longer. 20" vs. 30" LED strip and the light itself has 33% more LEDs.  Not saying it would be a perfect scenario, but it does "cover" better.

If you focus on the shadows on the substrate you can see the difference. The shorter, less powerful like does cast more, darker shadows.  For some plants this is the difference between growth and between withering away.

As far as what specifically is going on with your tank. I would suggest posting in the plant section with details, Test parameters, and a bit of explanation on your care for the plants.  There are some insanely talented plant people on the forums.  Many of them will be able to concisely help get things going for you.

This is that same tank now.   You can see the S. Repens doing much better.

The weird part is that usually they arrive, go gang-busters and then die.  I moved most of this from a 10 gallon into this 37 (about same footprint as 29, but like 3" or so deeper, I think).  It has a 30" Hygger 957 (48 watts).  Tanks looks wildly different now, the pogo is totally gone, it exploded in the new tank from about where the gourami is to what you see in like a week or so?  The stuff on the log is all doing very well. The sword in back corner is roughly the same, crypts roughly the same.  All the floating stuff is gone, but replaced with dwarf water lettuce.  Thinking back on the changes, I really think I'm going to remove all but a small hoop of aquarium tubing full of water lettuce.  It obviously soaks up a ton of light.  There's val in the way back that never gets any taller, but does spread and has several plants along the back now.  Good sized bush of java moss on top of the big log now.  I do regret a few things - indian almond leaves this worked really well for shrimp and overall looked neat.  But between that and the driftwood, even now the water is still tea stained when I change it.  Surprisingly so.  The almond leaves are gone, so it must be the wood now.  That has to block a lot of light (not in picture as the leaves were pretty new).  Also regret putting the light up on stilts, I did it thinking it would more evenly light everything, but didn't fully think what that would do to the light intensity.  I will say that it did really make the duckweed and the water lettuce I replaced it with really go crazy.  

I appreciate the discussion.  I do use AC root tabs, but I also struggle with keeping nitrate level in the tank so there's a lot going on here, I realize.  I don't think I have a single surviving pogo even a shrimpy one... which is a shame because I really like that plant.

February '22:

July '22 (glass not cleaned between February and July? you tell me lol):

I am ashamed to say that I don't have a more recent picture of what's in there now.  Fish stocking is quite different.  The rummys went to my discus tank, gourami had some disease and died after this pic within a day or two, in place of the rummys there are now eight kerri tetras.  Betta in place of the gourami went from 1 to 3 borneo suckers.  Will take a picture tonight or at least before I revamp the floaters and then see if I can't better wrangle in what I've got going on.  

Bottom line, I think I've convinced myself to put the light back on the rim of the tank and to pull all the floaters except a small amount that I can better control.  I remove TONS of water lettuce every couple weeks and it's just packed back in almost immediately.  

[nabokovfan87]

On 12/2/2022 at 9:03 AM, jwcarlson said:

The weird part is that usually they arrive, go gang-busters and then die. 

Ah, I see. There is definitely some fixes for this. Some methods. You're essentially dealing with some of the issues I had in my journal tank. It's definitely worth a read of you want to see all the small things I did that helped and screwed things up.  Have you had any algae issues at all?

Let me get the big screen so I can look up the photos better and check a few notes.  I'll try to break it down a bit as to what I went through and what might be related.

On 12/2/2022 at 9:03 AM, jwcarlson said:

I remove TONS of water lettuce every couple weeks and it's just packed back in almost immediately.  

Very indicative of what's going on.

[jwcarlson]

On 12/2/2022 at 1:22 PM, nabokovfan87 said:

Ah, I see. There is definitely some fixes for this. Some methods. You're essentially dealing with some of the issues I had in my journal tank. It's definitely worth a read of you want to see all the small things I did that helped and screwed things up.  Have you had any algae issues at all?

Let me get the big screen so I can look up the photos better and check a few notes.  I'll try to break it down a bit as to what I went through and what might be related.

Very indicative of what's going on.

No real algae issues after I turned lights down in the initial 10 gallon.  There's some green spot (I think) on the anubias that are highest up.  But it's not super bad.  I bought a couple of nerites because I read they liked green spot algae and they do seem to have been grazing on it, because it isn't gone, but it seems to be changing.  I cannot scrub or scrape it off.  I was going to try the "reverse respiration" to kill it and see if the shrimp will eat it.  But honestly, it isn't bad enough to bother.  It's not like it's a show tank!  There was some algae growing on one of the sides, but the snails, adult bristlenose, additional borneo suckers, and now a few very small bristlenose someone sent me have the sides all squeaky clean (on the inside, the outside is still a water spotted mess three minutes after I wipe it down haha).

I'll poke my head over to your journal and give it a look.  Sometimes just thinking through and writing out all off the stuff I've done helps me figure out what the probable issues are.  I think because there's so many water lettuce now, they'll basically out compete everything for the additional ferts because they're also way more able to soak the light.

[nabokovfan87]

On 12/2/2022 at 11:33 AM, jwcarlson said:

I'll poke my head over to your journal and give it a look.  Sometimes just thinking through and writing out all off the stuff I've done helps me figure out what the probable issues are.  I think because there's so many water lettuce now, they'll basically out compete everything for the additional ferts because they're also way more able to soak the light.

yeah exactly.  The floating plants do well because they have carbon access and direct light.  In a tank with lower demand, lower power lights (if that is the case) then it would make sense that those plants do a little better.  I agree about writing things down and how it helps.

Let's take a look...

The plants in the substrate likely need some root tabs. If you're not seeing moss grow you're issue is either carbon or fertilizers.  PSO/Watersprite will take a lot of ferts and will basically grow until they block the light out. They can grow really fast if you feed them and there isn't algae issues.  What is your fert schedule, how much are you dosing and how often?  The stems you have floating, plant them in the substrate and add some root tabs around them (not directly under them) so that the roots can take hold.  This helps because you can then make sure your light is a variable instead of only feeding those two up top.  If the PSO/Sprite needs more light just to show growth, then you're really looking at the crux of the issue for the tank. 

Right now, let's add some root tabs, review dosing, get the light on the rim of the tank and turned up slightly and see what that does for the next couple of weeks.
 

On 12/2/2022 at 11:33 AM, jwcarlson said:

There's some green spot (I think) on the anubias that are highest up.  But it's not super bad.

I wouldn't worry about green spot or brown diatoms unless they are prevalent. If it's on the glass I just scrape the front (sometimes the sides when it's bad), but the good thing is you don't have the nastier forms of algae.

[jwcarlson]

On 12/2/2022 at 2:19 PM, nabokovfan87 said:

Right now, let's add some root tabs, review dosing, get the light on the rim of the tank and turned up slightly and see what that does for the next couple of weeks.
 

I wouldn't worry about green spot or brown diatoms unless they are prevalent. If it's on the glass I just scrape the front (sometimes the sides when it's bad), but the good thing is you don't have the nastier forms of algae.

 

I am not religious about root tabs, basically because of the lack of water changes.  But I have been trying to do a WC every two weeks (about 50%) and adding root tabs at that time.  Similar issue in a 10 gallon with the stem plants, but they're in Fluval Stratum.

Dosing I am also not perfect on because I frequently forget.  I'd say on average I'm doing a pump of Easy Green per day, but usually doing it every 3-4 days.  Meaning that I'll do 4-6 pumps in the 37 gallon every 3-6 days.  And I don't necessarily feed all the fish every day.  I would really benefit from an autodosing system because even with two separate bottles, I am still almost never remembering to dose. 😄

Lighting in the 37 gallon is from 11 AM to 7:30.  10 gallon is 2 PM to 7:30 because there was some staghorn and hair algae that showed up, but that was (I believe) existing from my bucket'o'plants which was a lawless bucket of primordial goo that had all sorts of bad stuff going on.  I've been removing that algae when I see it and haven't noticed much anymore.  When I initially set the tanks but, I did have some algae, but I cut off the blue lights to "off" instead of them running automatically for like an hour or more for "dusk".  I will say that the 37's HOB does have quite the algae-fall growing on the outfall of the filter.  This happened when I bumped the light up.  I just occasionally pull it off it it gets too long, but I honestly kind of like it because the shrimp and snails are always jumping up into the filter and are neat to watch surfing around up there.  I would assume when I knock the light down it will eventually die off.

Edited December 2, 2022 by jwcarlson

[jwcarlson]

Current status.  Due for floater clean out, though they are always dense.  It's important to note that the stem plant dwindling happened before I added floaters for the most part.  And I forgot there was pothos in there!  Looking at it objectively it might be a miracle anything but the water lettuce is alive. 🤣

 

[jwcarlson]

Here's today.  Cleared out 90% of the water lettuce.  Nitrate was at 10 PPM before water change.  It's really cloudy from refilling and two weeks ago I pulled the polishing floss and it's just had lots of solids floating since.

Anyway, clearly a lot more light now.