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Non co2 17 US gallon re-start with PAR readings

faizal

Member
Joined
1 Mar 2011
Messages
968
Location
Alor Setar , Malaysia
Hi,...after my last attempt at a co2 enriched tank went down badly I sort of went into Low tech mode for sometime due to time constraints mainly,....the tank is lit by 2 CFLs @ 8 watts each,...and currently about a month into setup,...most of the stems melted ( Ceratopteris Thalictroides,cabomba caroliniana, limnophila, and recentely the bacopa caroliniana) . I had reduced the lightig level by turning the CFLs towards the wall at the back of my tank. My reason for doing that was:

1. There were some hair algae on some of the Ceratopteris thalictroides,..followed by stem melt of the plant some 2-3 weeks into the set up.

2. Some diatom algaes on the hardscapes and front glass,...despite the fact that I had kept old my filters running prior to the non co2 restart phase.

Here's how the tank looked as of 3 days ago:

11062011133.jpg


Today,...I finally got my Apogee MQ200 that I had long been saving up for.

When I took the measurements ,...I was quite shocked to find out my PAR values at various parts of the tank,....

At just below the water surface level 4- 6 mmols/sec/m2
Average PAR at substrate level is horrible,.... :( 0- 4 mmols/sec/m2

If you look my grainy picture :oops: above ,....you could probably make out 3 stems of Bacopa Caroliniana at the Left Midground area of the tank,...the PAR at the stem base is 1 mmol/sec/m2 and the PAR readings at their apical shoots are around 4-5 mmol/sec/m2

Is this the reason why most of my stems slowly melted away over a 2-3 week period? Too low light levels (i.e. Below light compensation point)??? :wideyed:
If so,...how does this explain why the other plants are doing well.

Please don't get me wrong though,...most of the other plants are doing quite well,...like Crypt Tropica, Hygrophila Difformis (PAR near these plants are between 2-4 only),..The large Anubias at the left bachground (PAR reading ranges between 4 - 0 here) and H. Polysperma at the right background area ( PAR range is 2 - 6) are doing surprisingly well,..infact 2 of the C. Tropica is giving off a new shoot on each of them.

But another crypt tropica situated at the same area of the tank (i.e. foreground centre with a PAR of 1-3) is somewhat melting slowly as of today.



What would be an ideal substrate level & below water surface level PAR values that one can work with in a non co2 set up please?

I'd really appreciate any inputs.

Faizal
 
Hi,

I'm not an expert but I think that in the photo you have a lot more PAR than your readings are telling you. That's just too low. Could it be that you are working with different units (e.g. micromols.m-2.sec-1).

cheers,

GM
 
Hi gmartins :D ,....yes you are right,...that photo was taken with extra lighting because I couldn't get a decent picture with the original lighting levels. So I had to turn the lights directly onto the tank. Usually I keep the light away from the water column to reduce its intensity after I saw some plant melt & hair algae.

:oops: Opps!!! Sorry again !!! It DOES say here on the meter "Micromol. m-2. sec-1 "

I got the units wrong but the value of the readings are above as I had explained.

So,....they are still low?

I remember Clive saying that Light Compensation Point for most plants are between 10-20 micromol/m2/sec. So is it safe to presume that I can increase my light levels at the substrate level to at least 10- 20 micromoles. I am using Compact Spiral flourescent Lights currently at 8 watts each.
 
I guess I was trying to reduce the co2 stress during the transition phase of the plants into the non co2 mode and sort of went overboard with the light intensity reduction.

"Keep on going faizal,....one step at a time,......you'll get your break soon enough "

:rolleyes:
 
There's a price to pay going low tech (in particular low CO2) and that is you may not be able to grow all the plants you want. Often with low tech you chuck a load of plants in to your set up and see what grows well together.
I suspect the stem plants that melted were due to insufficient CO2 and not insufficient light- I have not had much luck with limnophila for example it always melts when I add it to my low tech tank while other plants thrive.

What is the volume of your tank btw?
Are you adding any form of CO2? ie liquid C or organic matter in substrate?

Ultimately the choice and quantity of plants you can grow will be determined by CO2 as ferts and lighting, the other important factors are alot easier to control.
 
Hey Brenmuk,... :)

My tank is 17 US Gallons.
I am not adding any forms of carbon at all .
Ferts : Once a week . I dose 3 weeks & let it go for a week without dosing .
Topping off evaporated water now & then

1/4 Teaspoon Seachem Equilibrium
1/8 teaspoon KNO3
1/32 teaspoon KH2PO4

Equilibrium & macros dosed on separate days

No peat or leonardite in my substrate,....just Seachem's Flourite.

Brenmuk said:
Ultimately the choice and quantity of plants you can grow will be determined by CO2 as ferts and lighting, the other important factors are alot easier to control.

Couldn't agree with you more but then my PAR Levels had been way way below LCP for most plants,....so I was wondering if my extremely low lighting levels could have contributed significantly to the stems' melting.

I have now adjusted my lighting levels

PAR at substrate level : 9-10 micromol / m2 / sec
Just below water surface ,....around 20 micromoles

I am a bit daunted to increase the light levels beyond these figures (in view of the non co2 environment of the tank)

I guess all I could do now is wait & observe the plants and look for any signs of co2 related algae.

Just to share this with everyone,....I cannot believe how fast the PAR level drops in a CFL . Point blank range right next to the bulb it measured about 150-220 & then just 1.5 inches further down even before the water surface level is reached,....it reads around 50 :wideyed: . No wonder we could use more WPG using the CFLs.
 
Hi Faizal,
I cannot explain the PAR readings unless the bulbs are emitting a large percentage of their energy in the far red beyond the response of the sensor. Melting is a CO2 issue as indicated previously. Plants have not only a Light Compensation Point but they also have a CO2 Compensation Point, where they require at least some minimum CO2 level in order to produce as much food as they consume. Plants that do not do well in non-enriched tanks simply cannot cope with the low CO2 levels due to their higher CO2 Compensation Points.

Plants that survive in low CO2 environments also have a strategy to first generate and then pull CO2 from the water column. This is accomplished by converting the Bicarbonate (HCO3-) in the water to CO2. The plant produces acid (H+) and secretes it into the water. The converted CO2 is then available for uptake. Plants such as Vallis are famous for this ability, but only 50% or so of aquatic plants are able to accomplish this. This explains to some extent why various plants thrive in CO2 poor waters while others fail.

Since you experienced melting and hair algae when you had higher light, it does not follow that the melting that you have now is associated with the lower lighting levels. It's unclear at this point whether you have a light issue or CO2 issue, however we know, as Brenmuk pointed out that there is a 95% chance that this is a CO2 issue. If it does turn out to be a low light issue then this would be one of those rare cases. :geek:

Cheers,
 
Wow,...this IS a tricky one isn't it?

Okay then,.....currently as i mentioned I am using 2 lights bulbs ( Compact Spiral Fluorescent) . Both the lights were previously directed 90% facing towards the wall rear to my aquarium. Now I have made them face directly down towards the water column.

The new PAR readings are around 10 at substrate & around 20 @ water surface level.




So,...would it be okay if I just watch the tank for about 2 weeks or so,....and see if there are any signs of hair algae or melt on any of the existing plants that are currently doing well without any issues,....

Correct me if I am wrong but the things that I should be looking out for are:

1. Hair algae
2. Sudden melt on previously well & healthy plants
3. Sudden onset of diatom algae outbreak

ceg4048 said:
Hi Faizal,
I cannot explain the PAR readings unless the bulbs are emitting a large percentage of their energy in the far red beyond the response of the sensor.
Cheers,

It says Cool Daylight on the compact spiral fluorescent.

I don't understand this Clive :oops: . I am sorry but I am not sure what you meant by "....beyond the response of the sensor.". I thought PAR is what grows plants regardless of the light spectrum . Do you think that the plants are actually being exposed to higher PAR values that what the sensor is telling me? Oh,....gosh. :sick: That really makes me Donkey , doesn't it? (Shrek's mate). But I thought Tom Barr said that the Apogee is reliable. This stuff is not cheap.

I am confused again :oops:

I am sure there's has never been another soul as crazy as I am taking PAR readings on a non co2 tank. I am sorry for being such an a*s but I am doing this so I could understand what goes on in a tank. :oops:

Truly sorry for all the hassles guys.

Faizal
 
ceg4048 said:
Since you experienced melting and hair algae when you had higher light, it does not follow that the melting that you have now is associated with the lower lighting levels. It's unclear at this point whether you have a light issue or CO2 issue, however we know, as Brenmuk pointed out that there is a 95% chance that this is a CO2 issue. If it does turn out to be a low light issue then this would be one of those rare cases. :geek:
Cheers,

:silent:OOPS!!! Err,.... There's something I had left out unintentionally but which I feel that might be a wee bit of importance because I suddenly remembered this after re-reading your post .

The initial stem melt and hair algae which I had with the tank was under the original t5 lights total wattage of 18 watts over my 17 US Gallon tank. This Lighting was reduced a little by covering it with some tissue papers. It was during this period that I had severe stem melts ( Cabombas went first,...followed by Limnophila sessiliflora,...then the Bacopa Caroliniana and finally the Ludwigia Glandulosa). This was about 2-3 weeks into the setup. Then 2 weeks ago,....I changed the lighting to the current 2 Compact spiral Fluorescent ones,...and sort of drastically reduced the light levels. The lighting level was so reduced that the tank was practically in shadows even during the photoperiod!!!

Like I mentioned,...90% of the light rays were directed to the wall behind my aquarium. And I was so surprised that the anubias were doing well,...the H. Polysperma which were closest to the light source were doing well but a single Crypt. Tropica & the 3 stems of bacopa (which were all further away from the light) sort of started a very slow melt,...which I initially also thought was a co2 issue but had a change of heart when I took the PAR readings.

So for what it is worth my dear friends,....I am going to go with my gut instinct here and trust the very expensive PAR meter for awhile & stick to my current lighting levels and also keep a close watch over the tank.

If my PAR readings are correct,....then the PAR at substrate & water surface are just at the LCP for most plants,...and theoretically things should improve like slightly better growth rates & no melting should this truly turn out to be one of those rare cases. If turns out to be a co2 issue,....then i don't know how I could possibly overcome such an issue because I cannot reduce the lighting levels any further than what it had been over the past 2 weeks,....as believe me,...it would be near total darkness in there DURING the lights-on period. :crazy:

The above picture of my tank was taken with extra lighting,....that was not the usual photoperiod lighting intensity of my tank over the last 2 weeks.
 
faizal said:
If my PAR readings are correct,....then the PAR at substrate & water surface are just at the LCP for most plants,...and theoretically things should improve like slightly better growth rates & no melting should this truly turn out to be one of those rare cases. If turns out to be a co2 issue,....then i don't know how I could possibly overcome such an issue because I cannot reduce the lighting levels any further than what it had been over the past 2 weeks,....as believe me,...it would be near total darkness in there DURING the lights-on period. :crazy:

Some ways to manage CO2 in a low tech tank that has no CO2 enrichment are

1)Reduce light intensity - which I believe you have done.
2)Reduce photo period - I usually start off at about 10 hrs and increase to max 12 hrs or min 6hrs as necessary.

3)Add shade with floating plants (further reduces light) and floating plants get CO2 directly from air
4)Allow plants to grow partly emmersed, many plants will send leaves and part of their stems to the surface so they can use aerial CO2.

5)Add more bio load and feed more - but don't overstock - more fish waste when it breaks down means more plant food including CO2.

6)Prune - demand for CO2 is related to the total amount of plants so pruning your plants periodically as part of your maintenance will allow you to keep plant demand for CO2 at manageable levels.

So you see there are ways to manage CO2 levels in a low tech tank that do not solely rely on lowering light levels. Anyway you will want a certain amount of light intensity and photo period for the health of the tank and for aesthetic purposes - you want to be able to see your tank :rolleyes: .
 
Thanks Brenmuk,.....truly appreciated your concern.
Okay this is what I have been doing.


1. Light Intensity: As you well know is reduced.

2.My photoperiod is 5 hrs ( Remember the first time you advised me to keep it at 5 hrs because I told you I had just flourite for substrate,...well it's been running for 5 hrs ever since)

3. Floating plants are there but not covering 25% of the surface,...I am concerned because the PAR is already low & I fear adding more might reduce it further.

4. Once / Should the H. Polyspermas hit the water surface,...I promise to let it grow out of the water. It;s half way up there.

I just hope the PAR readings are reliable. Nothing to do right now but wait ,...correct?

Thanks for helping. Just a curiosity though,...did you guys have this much difficulty growing plants when you were at my stage?
 
faizal said:
Thanks for helping. Just a curiosity though,...did you guys have this much difficulty growing plants when you were at my stage?

Have look at my journal (signature) as I said before I went with mostly easy to grow undemanding plants and had mixed results with more demanding plants.
 
Nice,..... :)

Hey what do you call that large leafed plant in your last picture?
Do you use T8 fluorescent lamps there?
 
Brenmuk said:
faizal said:
Thanks for helping. Just a curiosity though,...did you guys have this much difficulty growing plants when you were at my stage?

Have look at my journal (signature) as I said before I went with mostly easy to grow undemanding plants and had mixed results with more demanding plants.


Its some nymphaea species 'Tiger lotus'. I don't know the exact species but a great plant that produced large attractive leaves that eventually made it to the surface and provided quite a bit of dappled shade.
 
You are right Sanj,....so I will currently be increasing the intensity a bit to 20 micromols (Substrate) and 40 micromols/m2/sec at just below water surface today. Just as Clive had pointed out,.... I am not sure if it's a co2 or lighting issue currently,...

So,....i am increasing the light levels a bit & I guess I just have to wait & see. Unfortunately,...there's only one way to know for sure. :rolleyes:

Wish me luck

Faizal
 
Just a quick update guys,...

The light is now 20-ish micromol/ m2 / sec @ substrate and about 40-ish at just below water surface level.(Mr Barr's recommendation,....errr,...yeah I sort of pestered him a few days back). Not a perfect even spread of light as one might want it to be,....but I hope it'll do under the circumstances.

it's been like this(the current lighting intensity) for about 4 days now. It's a non co2 tank,...so I am kind of expecting things to happen over a 3 week window period ( i.e. slowly) but so far there has been no melt yet. But I don't want to be overconfident either,...just keeping a close watch over things. I have learned now that It's way too early to say anything.

I have also added a bunch of extra plants,....in view of keeping the plant mass up as advised. Day 3 on that now.

Here's a sample pic of how the tank looked as of last night : (sorry for the grainy pics,...i am still taking these shots with my cellphone)


22062011148.jpg


The plant list :

Hygrophila Polysperma, Anubias of various varieties, Crypt parva, Crypt Tropica, another purplish long leaf variety of a Crypt, Egeria Densa ( yes,...I couldn't resist), Cockscrew Vals & Amazon Swords.

If this tank pulls through folks,....it would truly be my first.

Please please God let it work!!!! :)

Faizal

P.S.--> Valuable lesson learned over the last couple of months,...& note to self : Learn to ride a bicycle without your training wheels first. Then you could have a go on that cool looking superbike!!
 
Hi faizal

This looking nice.
faizal said:
It's a non co2 tank,...so I am kind of expecting things to happen over a 3 week window period ( i.e. slowly) but so far there has been no melt yet.
Do not be surprised if the changes take longer than that :wideyed:
Some changes take 3 weeks to occur in a CO2 injected tank and the growth rates are 5-10x faster than non CO2 injected tanks.
 
:) Thanks Ceejay.

CeeJay said:
Do not be surprised if the changes take longer than that :wideyed:
Some changes take 3 weeks to occur in a CO2 injected tank and the growth rates are 5-10x faster than non CO2 injected tanks.

I'll be sure to keep that in mind.

Thanks again.

Faizal
 
Hi,... :)

It's been excatly 8 weeks since I first set this tank up. The Egeria densa that you see there in that picture is currently gone as it was getting too messy. The Hornworts that I put in replacing the egeria appeared to be quite messy as well. Too brittle ,...just like Darrel said. So it had to go. A shame really because it WAS really beautiful.

Anyways,...the other plants are doing quite well. Hygrophila polysperma has let out so many tiny shoots, Crypt Tropica, Crypt wendtii, crypt petchii, crypt parva have all given out new shoots (after an initial mild melt ,...despite the fact that I had reduced the no of their leaves during planting).

Last night I planted some Hygrophila sp Tiger, more of crypt tropica & wendtii to fill up the empty spaces.

Ceejay,...you were right. Some changes DO take more than 3 weeks in the tank. :D

Thanks for looking.
 
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