Why can't I grow healthy plants? What am I missing? - Now improving!

[Nick Norman]

I set up my tank over three years ago with easy plants dosing liquid carbon and macros and micros. I had some luck with some plants (mainly ferns, anubias and crypts) but stems never grew that well.

About a year ago I decided to try pressurised co2 and re-scape in the hope of having a lush green tank with stems.

Unfortunately I haven’t had much success. The stems are alive and grow but are very stunted and leggy. The growth is so slow with older leaves growing algae.

I removed most of the algae at one point and tried less light but the algae grew back and the plants didn’t improve and just stopped growing.

I have spent many hours reading info on this forum and implementing the advice given. I am now at a loss as to why my tank is so far off the health of tanks on this forum.

I haven’t yet tried lots more light. Everything I have read says more light isn’t the answer. I recently added a 7 watt led, the growth rate increased a bit but so did the algae.

Tank

The tank is 80 x 40 x 45cm High, Approx. 120ltr with hardscape.

Lights

Current lights are two 50cm aquaray aqaubars 12watts each. And a DIY 6000K 7w led strip recently added. All are 18 cm above water line, 56 cm above lowest point of substrate.

Filter/Flow

Filter is a sunsun 302 rated at 1000 l/h (actual turnover 400 l/h) to a spray bar across half the back glass facing the front glass.

Also have a Hydor Koralia Nano 900 on the other half the back glass facing the front glass.

Substrate

ADA aquasoil 80% 3 years old, 20% 1 year old.

Ferts

50% weekly water change

API test kit: GH 15, KH 9

Thames water nitrate reading: 30ppm

I dose EI with half the recommended nitrate as tap water has nitrate.

Macros

500ml solution from dry salts dosing 50ml 3 times a week

K3PO4: 2 grams = 1.3 ppm of P per dose.

KNO3: 7 grams = 3.9 ppm of N and 2.5 of K per dose

K2SO4: 14 grams = 5.7 ppm of K per dose.

Micros

TNC trace (dry ferts). I add the amount advised by TNC on alternate days from Macros.

Co2

It took a while to get the co2 as it is.
I have had it set up like this at 6 bps for a few months now with no improvement to plants.

Co2 from FE at 6 bps.

The co2 is delivered through an UP inline atomizer into an APS EF-2 filter booster as a reactor to a spray bar across half the rear glass facing forward.

Last PH profile:

Tank water left in a cup for 24 hours: 8.26

07:00 7.81
12:00 7.84 Co2 on
13.00 7.11
14:00 6.77 Lights on.
15:00 6.67
16:00 6.65
17:00 6.65
18:30 6.63 co2 off
19:00 6.68
19:30 6.75
20:30 6.89
21:00 6.96 lights off


So what next? I don’t want to give up but don’t want to waste any more money and time on stuff if it’s not going to improve anything. I have considered starting again with new plants and substrate but don't want to end back where i am now.

I have been removed the majority of the algae when implementing a change but it has always grown back. I have a feeling I just need to continue to improve on the same things, Co2, flow and maintenance. Just hoping there was something I was missing that someone on here could tell me. The plants are so unhealthy there must be something drastically wrong!

 

[Zeus.]

Hi Nick

Thanks for all the info on your setup, you have been trying hard.
My initial thoughts are not enough light as plants are stunted and leggy. In most tanks users use too much light. IMO your at the other end of the spectrum

 

[Zeus.]

Opps

Not sure of the output of your lights, but have with one off my tanks been in the same situation, you focus on the algea and not the poor growth so you turn the lights down. The short laggy stems IMO are the key. Low light intensity leads to the PAR getting to the plants being just enough but plenty for algea.
I may be wrong so interested to see what others with more experience have to advise

 

[Iain Sutherland]

Hey Nick,

I'm sorry you having issues as on paper you are doing all the right things.
As Zeus has said the light levels may be an issue however personally I think you should start with looking at the flow.
The spray bar doesn't have much gusto, ideally the flow would hit the front of the tank when above water level, the action of the atomizor and inline heater will be reducing what is already an underpowered flow set up. I appreciate there is a small powerhead in there as well which helps but from experience powerheads just don't seem to work as well as filter outlets as the output of them is a big rose head and not very directional.

As a cheap option prior to new filter or lights try adding another powerhead, give the tank a really good clean, when you do this waft your hand around the plants and hardscape to stir up the detritus, clean the filter, trim heavily damaged/weak/algae covered plants out, put new drop check fluid in and place it in an area without direct flow and if possible add a good bunch of rotala or other fast growing stem somewhere ( this can be your canary, if that starts to degrade also then the changes you have made aren't working)

Up the water changes to twice weekly 50% and then wait at least 2 weeks.
If this hasn't started to show improvement then you can move on to alternative and possibly more expensive options such as lighting.

Keep us updated with what you do and how it goes, between us you will have a lush tank in a few months

Sent from my SM-G950F using Tapatalk

 

[rebel]

I suggest doubling light output .Remove algae daily . You will know in 2 weeks .

You should be commended for sticking with it for this long!--

Btw if no results, double lights again .

 

[Edvet]

ooking at the flow.

my vote as wel, doesn't look like the CO2 reaches . Plants grow wel in low light, just slow. pH keeps falling when the lights are on, pH should bottom out in an hour or two. This points to distribution and dissolving problems.
Increasing the maintenance will help ofcourse,

 

[ceg4048]

This is a flow distribution problem and has nothing to do with light.
Leggy growth is a symptom of poor flow/distribution.

As Ian points out, there is a severe lack of energy coming from the spraybar.
Additionally, it's position is too far to the right and the powerhead is too far to the left.

I have no idea what is a "APS EF-2 filter booster as a reactor "
If it is a reactor then it seems pointless because you mention that you have installed an Up atomizer?

So the tepid flow rate from the spraybar means that :
A. There is too much media in the filter
B. There are fittings or connectors that are reducing the cross sectional area of the piping.
C. The APS device is install in such a way as to conflict with the filter flow.

Or any combination of the above.

After addressing the flow, next is to reconfigure the spraybar and powerhead so that the better compliment each other.
They should be centralize so that there is an equal distance between the powerhead and the left wall as there is from the end of the spraybar and the right wall.

Another possibility is to centralize the spraybar and place the powerhead either above or below the bar at the midpoint.

Flow/distribution is something that you really have to play with to get it right for your specific tank, but these are good starting points.

Cheers,

 

[Nick Norman]

Thanks for your responses. It makes sense to improve the flow before adding more light. I thought i had improved the flow a lot when changing to pressurised co2 by making smaller holes in the spray bar and spaced them farther apart and added the power head. I have seen vids/images of members tanks with spray bars the full length hitting the front glass so i suppose my flow is far from optimal.

I have no idea what is a "APS EF-2 filter booster as a reactor "
If it is a reactor then it seems pointless because you mention that you have installed an Up atomizer?

I first had just the up atomiser and had lots of micro bubbles which collected on the surface and large bubbles now and again. I added the filter booster for the co2 to dissolve in before reaching the tank. It has no media in, just a bucket with the flow going in through the top and out through the bottom. It seams to work as I have no bubbles in the tank.

The sunsun filter isn't very strong. I tested it with and without the heater and filter booster, just the spray bar at tank height and it took the same time to fill a 30ltr bucket. (400 lph) The filter has in it course filter sponge in one tray and a bag of ceramic filter rings in each of the other two.

I will re position the power head and filter as suggested and see if I can get any more flow out of the filter. I could try another power head or maybe get a better filter. Then will trim, clean as advised and do two weekly 50% water changes and see what happens.

If i was to upgrade the filter what filter would give me enough flow along the whole length of the tank without the need for powerheads? What lph would I need as the filters don't produce stated flow? would this be achievable with one filter or would i need two?

Thanks again for the advice.

 

[techfool]

My lighting is seriously crappy (I got a kit aquarium from petsathome) which I have on for less than six hours a day and I think my plants are okay. They won't win any prizes but I just divided a crypt and my dwarf sag has gone crazy.
I also have an internal filter and when that bungs up I notice that the plants start to look dirty. You want so see your plants waving in it. You don't want the debris in your aquarium collecting in your plant leaves. It's an algae magnet.

 

[ceg4048]

I first had just the up atomiser and had lots of micro bubbles which collected on the surface and large bubbles now and again. I added the filter booster for the co2 to dissolve in before reaching the tank. It has no media in, just a bucket with the flow going in through the top and out through the bottom. It seams to work as I have no bubbles in the tank.

OK, well, I mean generally, when you have that symptom of bubbles collecting on the surface, it means that the flow rate is poor and the bubbles are not making it to the bottom of the tank. The result is that the CO2 concentration is high near the water's surface, but is low in the plant beds where it is needed the most. Even if your booster does a better job of dissolving the bubbles, the problem of poor flow still exists and so the well dissolved water remains nearer the surface and is not being pushed down to the substrate.

The sunsun filter isn't very strong. I tested it with and without the heater and filter booster, just the spray bar at tank height and it took the same time to fill a 30ltr bucket. (400 lph) The filter has in it course filter sponge in one tray and a bag of ceramic filter rings in each of the other two.

This is not atypical of filters and pumps in general. Manufacturers claims are always optimistic. 40% of rated flow is normal when the filter is sitting below the water level and is filled with media. The ceramic rings do the most damage to flow rate. I would suggest to replace these with something more light weight such as activated carbon, or simply reduce the amount of the rigs by 50% or more. See if the flow improves.

I will re position the power head and filter as suggested and see if I can get any more flow out of the filter. I could try another power head or maybe get a better filter. Then will trim, clean as advised and do two weekly 50% water changes and see what happens.

If i was to upgrade the filter what filter would give me enough flow along the whole length of the tank without the need for powerheads? What lph would I need as the filters don't produce stated flow? would this be achievable with one filter or would i need two?

Well, I dislike advising people to spend more money if there is an inexpensive way to improve the tank. I reckon the best way is to start with experimentation of the positioning. Sometimes that does the trick. Also, you mentioned that you changed the hole sizes in the spraybar. Sometimes this actually has negative consequences. It is more important to have a high mass flow rate, not necessarily a higher velocity. We want to move as much water with high momentum down to the bottom. If you restrict the hole size too much then you actually reduce the mass flow rate.

The next cheaper thing of course, is to use another powerhead, but then the tank starts to look really cheesy with rocket boosters strapped to the back of the tank.

Ideally, a 120L tank should use a 1200 LPH rated filter, but this Sun Sun unit should work. You should be able to eek out perhaps nearly another 100 LPH by reducing or eliminating those noodles. and better positioning of the bar and powerhead should help a lot. You really ought not to need a additional or a different filter. Also make sure your hoses are not being kinked somewhere along the circuit.

Have a go with these tricks first and see how it goes.

Cheers,

 

[rebel]

symptom of bubbles collecting on the surface, it means that the flow rate is poor and the bubbles are not making it to the bottom of the tank. The result is that the CO2 concentration is high near the water's surface, but is low in the plant beds where it is needed the most. Even if your booster does a better job of dissolving the bubbles, the problem of poor flow still exists and so the well dissolved water remains nearer the surface and is not being pushed down to the substrate.

Agree with this. Sometimes this indicates poor O2 as there is a oily film in the surface preventing the bubbles from bursting. A skimmer of the sorts may help.

A cheaper way to do this is to lift your output to cause some turbulance.

 

[Zeus.]

This is a flow distribution problem and has nothing to do with light.
Leggy growth is a symptom of poor flow/distribution.

Thanks for correcting us lesser mortals😳 Think there may off been a dimensional parrelel universe vortex issue with twin locations locally around me and Rebel which would account for the changes in the laws of our universe
Flow/distribution is King when injecting CO2 and always the first
Cultrip one should investigate/suspect.

sizes in the spraybar. Sometimes this actually has negative consequences. It is more important to have a high mass flow rate, not necessarily a higher velocity. We want to move as much water with high momentum down to the bottom. If you restrict the hole size too much then you actually reduce the mass flow rate.

Very tricky getting to hole size right IME More output can be less turnover like no spray compared to spraybars. Then spraybar positioning, angle, more holes, less holes, bigger, smaller trail and error, rinse repeat.

 

[Nick Norman]

The ceramic rings do the most damage to flow rate. I would suggest to replace these with something more light weight such as activated carbon, or simply reduce the amount of the rigs by 50% or more

How much biological filtration do i need for 140ltr (120ltr with hardscape) tank? will one large fist size bag of ceramic rings with a layer of 25 mm course foam be enough?

Think I have a bag of active carbon somewhere, if I left it in permanently would it act as biological filtration? I could replace one of the bags of the ceramic rings or maybe both.

i will have a play around to see what if I can get any more flow out of the filter, test to see at what point the flow is being lost. Maybe I can improve the spray bar and connections.

Cheers.

 

[Zeus.]

How much biological filtration do i need for 140ltr (120ltr with hardscape) tank? will one large fist size bag of ceramic rings with a layer of 25 mm course foam be enough?

bio media for fluval 305

 

[dw1305]

Hi all,

So what next? I don’t want to give up but don’t want to waste any more money and time on stuff if it’s not going to improve anything. I have considered starting again with new plants and substrate but don't want to end back where i am now.

I think you should be all right, and that your plants will eventually grow, if you can sort out your CO2 issues.

I had some luck with some plants (mainly ferns, anubias and crypts)......

These are good plants for long term set ups, a lot of people eventually actually get fed up with the constant trimming and re-planting that stems require.

From the pictures your Amazon Frogbit (Limnobium laevigatum) looks pretty healthy, which is a promising start.
That suggests that it isn't a mineral nutrient issue, which really only leaves light and CO2 distribution as possibilities limiting plant growth.

Having said that if you don't dose any magnesium (Mg)? I would add some. "Epsom salts" are a cheap option, and about 10% magnesium. Water hardness in the States tends to include quite a lot of magnesium, due to <"geological reasons">, but that isn't true in the UK, where we usually need to add magnesium.

Have a look at the <"Duckweed Index">, it uses the leaf health and leaf colour of a floating plant (originally "Duckweed" Lemna minor, but Amazon Forgbit is a better option) as an indicator of mineral nutrient levels.

Because Amazon Frogbit is a floating plant it has access to both aerial CO2 (400ppm CO2), and higher light intensity, than your submerged plants.

cheers Darrel

 

[HiNtZ]

That's a nice bit of frogbit

 

[ceg4048]

How much biological filtration do i need for 140ltr (120ltr with hardscape) tank? will one large fist size bag of ceramic rings with a layer of 25 mm course foam be enough?

The primary purpose of the ceramic rings is actually to slow the flow so that the larger particles of debris fall out of solution and to be trapped within the maze of rings. They do house bacteria, like any whetted surface but that is not their main function. That's why it's so critical to avoid these and to find better solution to mechanical filtration. Medium density foam, alfagrog, or scrrubbies work just fine.

Think I have a bag of active carbon somewhere, if I left it in permanently would it act as biological filtration? I could replace one of the bags of the ceramic rings or maybe both.

Yes, yes and yes!

Cheers,

 

[ceg4048]

Very tricky getting to hole size right IME More output can be less turnover like no spray compared to spraybars. Then spraybar positioning, angle, more holes, less holes, bigger, smaller trail and error, rinse repeat.

Yeah, for sure mate. What I do is to buy a length of cheap PVC tubing and then to try different lengths with different hole sizes. I try to get away with as short a length as I can with as large a hole size as I can. Sometime I use variable hole sizes along the bar. So for example you can try smaller holes at the front end (first two or three holes) so as not to drop the pressure too much and then larger holes the rest of the way. Check the flow rate with the bucket and see what works.

Flow/distribution is King when injecting CO2 and always the first
Cultrip one should investigate/suspect.

Definitely. Leggy growth is a sure sign of low CO2/O2 stress due to poor flow. The elongation between nodes is a result of poor gas exchange resulting in the buildup of the gaseous hormone Ethylene.

Have a look at the article for example https://academic.oup.com/aob/article/101/2/229/186522

I mention many times that in a CO2 enriched planted tank, flow is King and these are some of the top reasons. Gas exchange in a flooded plant is more important than anything else. It is more important than light and more even than nutrients.

Cheers,

 

[Zeus.]

Have a look at the article for example https://academic.oup.com/aob/article/101/2/229/186522

So correct me if I understand it wrong, but the production of the Ethylene by the researchers

Varies from plant species but it some it's the low [O2] found in deeper stagnating water is what stimulates the ethylene profuction which leads to elongation of the stems, but in other species the mystery pathway does not include an O2-requiring step. Most of the research was done on rice. I can understand the benefit of this to the plant OFC

When I have done a blackout intentionally and unintentionally I have observed elongation of stems of MC and crpyts as if the plants are trying to reach more light. During the blackouts the flow was unchanged but the elongation was still present? Maybe this is a different reason for elongation due to extended periods of no light! Which why us lesser mortals think elongation is due to not enough light?

 

[rebel]

I am very curious to see how this turns out.

Either way, if you are curious, just change one thing at a time and wait for two weeks before changing another. Keep a journal.