Siesta—helpful or no?

[Kwyet]

I want algae on my hardscape in my hillstream setup, but not on the plants. I’ve succeeded very well in growing it on the hardscape, have now added plants and reduced lighting, and I may have to reduce it more. Walstad and Rachel O’Leary both used a siesta period in low-tech setups and credited it with keeping algae off the plants, but I’ve seen others say it doesn’t do anything. What are your opinions/findings?
Thanks!

 

[RickyV]

Algae generally doesn't grow on healthy plant leaves. Whenever I've dosed heavily and had high lighting the plants were big and lush, and the glass/harscape covered in algae. Though now that I use large clean up crews I don't get much algae anymore other than some green spot on the glass. On smaller tanks as soon as I remove the snails I get a film of algae on the glass/hardscape but none on the plants.

 

[Kwyet]

Thanks! I’m not going to dose heavily because I’ll have hillstream loaches in there, also no CO2.

 

[RickyV]

Yeah you don't nessecarily need to dose heavy, lighting intensity and duration in my experience have a much stronger correlation with algae growth. Just dose enough to keep to the plants relatively healthy. Aquasoil in planted areas will also help. I currently dose my tanks pretty lean and get plenty of algae growth if I remove algae eaters.

 

[Pepere]

I run a split light schedule on one non injected tank. 4-8 AM and PM. The plants grow well and are free of visible algae.

My reason for doing this is for the early morning light every day in my bedroom to simulate summer sunrise for my Seasonal affective disorder. I suppose I could do a straight 8 hours in the morning just fine and yield the same benefit, but, I like seeing the tank in the evening too.

Personally I am not sold on the benefits of a siesta in terms of CO2 benefits for a non injected tank. Yes the co2 level rises during the dark period, and gets taken back up in the next light period, but it is co2 given off by the plants with the light being turned off. In my mind my assumption is that the CO2 being released by the plants were being utilized for photosynthesis while the light was on..

I do t think a siesta hurts the plants,but I am not sold on it being a significant benefit.

 

[Kwyet]

If I do a siesta, there will still be ambient light from a nearby window. Maybe that makes the whole question moot?

 

[ElleDee]

I have done both long term and in my experience it doesn't make a big difference one way or the other. I understand the theory behind it, but it just doesn't match up to my observations. Perhaps there are certain conditions where it matters, who knows. But if it's more convenient for your viewing enjoyment to split the lighting period or you just want to try it or whatever, go for it.

 

[Burr740]

Prefacing this to say I havent actually tested these methods personally with non-co2 tanks. But my opinion is if youre doing an actual walstad method, then follow her method including the siesta period. Walstad includes various "stuff" in the sub and elsewhere that produces co2 via decomposition and other actions. Also there's little to no surface agitation to reduce off-gassing. Which assumes the goal of having co2 higher than equilibrium with the atmosphere. If youre doing that then yes, a siesta will cause co2 levels to rise.

But I would question how effective this is in real time results, if these levels can be maintained at a consistent level long term (more co2 in the beginning vs 3 months down the road) Walstad isnt exactly growing any hard plants. Not sure what a side by side comparison would look like, siesta vs no siesta. My other question is at this point why not just add co2?

All that aside, I think its useless if youre just trying to get co2 back to equilibrium with the atmosphere. Strong surface agitation is your friend for that. A filter like marineland with the bio wheels. Anything to improve gaseous exchange at the surface. Because surface agitatiuon only off-gasses co2 if there's more in the tank than the atmosphere. If there's less in the tank, surface agitation causes it to increase in the tank, up to equilibrium

My other hypothetical problem with a siesta is that it just isnt natural. Plants open up and are in one mode during the day. They close up and switch to another mode at night. Throwing a 3-4 hour dark time in the middle of the day cycle just seems like itd be confusing for the plants, just my unsubstantiated opinion

I think @sudiorca 's low tech method is by far the best thing in the hobby for a non-co2 tank, esp if you want to grow something beyond the easiest of the easiest plants. He's got a journal or a thread or two here that describe his method. Its revolutionary really, grows some very difficult plants very well

 

[Koan]

He's got a journal or a thread or two here that describe his method. Its revolutionary really

Check out here and here

 

[Kwyet]

Thanks everyone! Really interesting insights. I think I’m not going to do a siesta based on your information. The tank is already set up. It’s not a Walstad. I’ve tried to base it on Rachel O’Leary’s hillstream tank, and she used a siesta, so I was seriously considering it. This tank has a coarse sand substrate, lots of surface agitation from a Fluval fx6 spray bar, and pretty easy plants—lots of crypts. I did put a sad-looking Madagascar Lace plant in there. If it doesn’t make it, no biggie.

 

[Tim Harrison]

Did a siesta period for a couple of years. Don't think it made much difference. Nice idea in principle. It's a good idea if your viewing time is split, with work for instance, that way you get to enjoy your tank more.

In a low energy tank I think good surface agitation is key. You get better gas exchange and CO2 conc. in the water, which should stay equilibrated with atmospheric CO2 levels throughout the photoperiod. I think consistency is of importance to plants.

If you don't want algae on plants it's perhaps best to put most nutrients in the substrate. And lean dose the water column with traces inc potassium. That way it's possible to introduce relatively higher lighting which may help grow algae in hardscape.

Nice looking tank btw.

 

[Kwyet]

Did a siesta period for a couple of years. Don't think it made much difference. Nice idea in principle. It's a good idea if your viewing time is split, with work for instance, that way you get to enjoy your tank more.

In a low energy tank I think good surface agitation is key. You get better gas exchange and CO2 conc. in the water, which should stay equilibrated with atmospheric CO2 levels throughout the photoperiod. I think consistency is of importance to plants.

If you don't want algae on plants it's perhaps best to put most nutrients in the substrate. And lean dose the water column with traces inc potassium. That way it's possible to introduce relatively higher lighting which may help grow algae in hardscape.

Nice looking tank btw.

From what I understand, root tabs give an initial boost to nearby plants, but then the nutrients quickly migrate into the water column, unless you’re using DIY Clay root tabs. I wonder if anyone has tested that? Is that your experience?

I don’t know how to make the clay kind, but I can look into it if I start having problems. I’ll be trying a bit of a balancing act though because I want the emersed plants and the epiphytes to do well too, without risking the loaches health. Fish come before plants for me, but I hope I can keep most of the plants in good shape too.

Thanks for your comments!

 

[Tim Harrison]

Yes good point. I was thinking more along the lines of a fertile substrate like soil capped by sand or gravel. I think if you dose traces and rely more on fish waste for Nitrates and phosphates your epiphytes, which are usually relatively slow growing should do well. Also depends somewhat on light intensity. But keep an eye on your plants they will tell you when they are hungry and then you can dose accordingly.

 

[Kwyet]

Yes good point. I was thinking more along the lines of a fertile substrate like soil capped by sand or gravel. I think if you dose traces and rely more on fish waste for Nitrates and phosphates your epiphytes, which are usually relatively slow growing should do well. Also depends somewhat on light intensity. But keep an eye on your plants they will tell you when they are hungry and then you can dose accordingly.

Okay, thanks! The tank is actually already set up with just a coarse sand substrate. I guess I should have asked beforehand, lol! I’m doing PPS-pro, which seems a good middle ground, and I can adjust that and the light as things develop.

 

[PeerUnk]

My two cents about a siesta and CO2 levels in a non CO2 injected tank:

I’m measuring the water pH and CO2 in a gas chamber via diffusion with a CO2 sensor. I’m logging the data every minute. My tank is non CO2 injected and pretty well aerated and fully stocked with plants. Looking at the data, I can tell you the impact of CO2 uptake by plants is there, but minor in comparison to the effect of:

• aeration and surface agitation itself combined with
• the effected of increased ambient CO2 level in the living room where the tank is at, when we all are at home, breathing out CO2 gas during the day, when plants are photosynthesizing.

The daily CO2 level swings between 1.3 and 1.9 ppm. I think the more stable you can get it via maximized CO2 diffusion with air, the better.

In a tank with surface scum, no agitation, no aeration and no CO2 injection and lots of fast growing plant, the plants which cannot supply theirselves with carbon via carbonates (HCO3/CO3) but must use CO2 cause they are evolved that way, will starve due to lack of CO2. I guess a siesta will help in that case, but lowering light intensity will help as well as a work around.

As suggested, no surface scum, good flow and surface agitation (and aeration to greater extend) will help much more to my experience.

 

[Kwyet]

My two cents about a siesta and CO2 levels in a non CO2 injected tank:

I’m measuring the water pH and CO2 in a gas chamber via diffusion with a CO2 sensor. I’m logging the data every minute. My tank is non CO2 injected and pretty well aerated and fully stocked with plants. Looking at the data, I can tell you the impact of CO2 uptake by plants is there, but minor in comparison to the effect of:

• aeration and surface agitation itself combined with
• the effected of increased ambient CO2 level in the living room where the tank is at, when we all are at home, breathing out CO2 gas during the day, when plants are photosynthesizing.

The CO2 level swings between 1 and 2 ppm.

In a tank with surface scum, no agitation, no aeration and no CO2 injection and lots of fast growing plant, the plants which cannot supply theirselves with carbon via carbonates (HCO3/CO3) but must use CO2 cause they are evolved that way, will starve due to lack of CO2. I guess a siesta will help in that case, but lowering light intensity will help as well as a work around.

As suggested, no surface scum, good flow and surface agitation (and aeration to greater extend) will help much more to my experience.

Thanks, that’s interesting! This tank has plenty of surface agitation and flow, and no scum. The new plants are developing some algae though. I think the high bay light and the aquarium light working together may be just too much, so I’ve turned the aquarium light off for the afternoon hours when the high bay grow light is on. I hope it won’t confuse the plants too much, since they still have light, just not the double whammy.

 

[ElleDee]

My two cents about a siesta and CO2 levels in a non CO2 injected tank:

I’m measuring the water pH and CO2 in a gas chamber via diffusion with a CO2 sensor. I’m logging the data every minute. My tank is non CO2 injected and pretty well aerated and fully stocked with plants. Looking at the data, I can tell you the impact of CO2 uptake by plants is there, but minor in comparison to the effect of:

• aeration and surface agitation itself combined with
• the effected of increased ambient CO2 level in the living room where the tank is at, when we all are at home, breathing out CO2 gas during the day, when plants are photosynthesizing.

The daily CO2 level swings between 1.3 and 1.9 ppm. I think the more stable you can get it via maximized CO2 diffusion with air, the better.

In a tank with surface scum, no agitation, no aeration and no CO2 injection and lots of fast growing plant, the plants which cannot supply theirselves with carbon via carbonates (HCO3/CO3) but must use CO2 cause they are evolved that way, will starve due to lack of CO2. I guess a siesta will help in that case, but lowering light intensity will help as well as a work around.

As suggested, no surface scum, good flow and surface agitation (and aeration to greater extend) will help much more to my experience.

I'm surprised that plant uptake of CO2 was so inconsequential. Is this with an inert substrate? What kinds of plants and how is their growth? Any livestock? I'm wondering if perhaps there isn't much endogenous CO2 generation in the tank.

 

[PeerUnk]

I'm surprised that plant uptake of CO2 was so inconsequential. Is this with an inert substrate? What kinds of plants and how is their growth? Any livestock? I'm wondering if perhaps there isn't much endogenous CO2 generation in the tank.

Hi,

The CO2 uptake by plants is definitely visible on the monitoring graphs, so not inconsequential as you might think.

But what I ment to say the effect of decent aeration (with ambient CO2 levels between 400 and 1200 ppm, monitored as well) on the aquatious CO2 level is clearly stronger than plant uptake during the day.

And that’s why I aerate the tank, as my hypothesis is that in a fully planted tank there is too less CO2 dissolved to support them during the entire day. So I’m a supporter for increased CO2 diffusion by aeration and strong (surface) flow.

And the effect of the aeration is clearly stronger than endogenous CO2 generation (clearly visible and the strongest during the night) as well.

I could show you some graphs and explanations for all these findings, but I rather write a separate article/thread for it.

I would agree if endogenous CO2 generation is bigger than in my tank, a siesta could help elevate CO2 level somewhat. I haven’t seen any measurements to support it though. Have you seen any? (I might shut down the aeration for a day and do a siesta to measure it.) But a siesta looks completely unnatural for me, why not decrease the light intensity to lower CO2 uptake?

Regarding your questions:

Substrate? Yes I have mostly inert gravel, but the substrate is more than 3 years old, full of gunk and sometimes it’s gets earth worm casting additions.

Plants? Fully stocked with mostly Bolbitis, Egeria, Nymphoides, Rotala, Cryptocoryne, Pogostemon Anubias and Lysimachia.

Livestock? Just 15x 4cm Tanichthys micagemmae, 300 Neocaridina shrimp and uncountable little snails in nett 550 liters.

I hope the respond isn’t too off topic. If so, let me know.
I'll start writing my own article, maybe my findings monitoring my tank will help others...