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Discussion Starter · #1 ·
I just started my Sachaem dosing yesterday and we will be leaving Saturday and gone for two nights. I can fertilize before I leave on Saturday but wont return till late Monday afternoon. I do not have anyone who can come do this for me. How would you handle it?
 

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i suppose you could leave your lights off for the 2 days you are gone. no need to fert. it will also do wonders if you have some problem algae (keep lights off for an additional day, do a major wc before you leave and after you return).
 

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unless you have an auto-doser, the simplest is to have a friend do it for you. just go through with them how much of each fert to put in. make sure it's someone who understands simple instructions.

i've have friends who are way smarter than me, but have the intelligence of a bag of wet hair when it comes to following verbal instructions.

and when they're there, they can feed the fish as well.
 

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Discussion Starter · #4 ·
Well I wish I had friends that live close enough to ask for help but I live in such a remote area it would be too long of a drive. I guess maybe i have to go back to short hours of light and no fertz until I get home. Hate to have to do that but I don't know what else I can do.
what is an auto doser and where can I get one? I wont be able to use this time but when I go back to work it would be nice to have since I work 12 hour days and the only time I will see my aquarium with the lights on would be on weekends unless i set the lights to come on several hours after I leave for work which means i need to dose a few hours after I leave for work.
 

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Hi Brownie,

I agree with both miles and JMHart - you can always cut back lighting and fert's for a couple of days with no harm done to most tanks. Once you get into High light, High Co2, and difficult plants it can become another matter. But still, a couple of days is not the end of the world.

Are you growing any high light plants? Any HC? (I've found HC can melt after a couple few days of no light ;)

As Miles said, If you are having any trouble with algae just turn the lights out for the time you are gone, you will come back to amazingly clear water.

Any large fish? anything that can't go for a couple of days without food?

Todd
 

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When I go out of town (even for 5 days), I dose the ferts for the time I'll be gone on the day I leave and have not had any major issues. If your lights are on a timer, that helps LOTS. You can get a timer for cheap at a hardware store (like Lowe's), or even WalMart.

If you don't have a timer for the lights, I'd leave them off for the 2 days and not worry about the dosing.

-Dave

Forgot to mention: if you dose all at once, dose the micros a couple hours apart from the macros to prevent precipitation and cloudiness.
 

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Discussion Starter · #8 ·
wow Dave monkey! You can fertilize that much ahead with no problem? I really like that idea, will give it a try
Thanks
 

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Plants can stockpile nutrients. They can store much, much more than they need to use in a single day or even a week without dosing.

Your plants won't have a problem with nutrients if you don't dose for the weekend.

On the other hand, plants can't live without light for very long. A week is about the longest you can keep most plants in the dark without harming them. Two days of darkness won't kill your plants, but it isn't doing them any good. The best choice would be to hook a timer up to the tank and set it for 8-10 hours a day. That way you won't have to worry about problems now or months into the future.
 

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Discussion Starter · #11 ·
freshwater, yes that is the tank but I have added more plants since then. I had to cut my lights to 5 hrs a day for over a week while I waited for my fertz. and one of my stem plants started looking pretty sad. Now that my light is back up it is starting to perk up and I really don't want to lose it since decent plants are so hard to get up here.
Think I will dose as usual and keep my fingers crossed.
Thank you everyone for your help and suggestions
 

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I wouldn't cut lights in half, you will get stringy growth. Simple solution leave full intensity but knock photoperiod down to 2 hours. This way the phytochrome response still triggers high light growth but the plants metabolism is forced to slow down.
 

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2 hours of light a day? Seems a little on the skimpy side even with intense lights. Plants need to accumulate a certain amount of sugars each day to grow, the photosynthesis reaction can only work so fast, and there comes a point at which more light won't = more photosynthesis. The only way to get the sugars is by having a long enough photoperiod. The lowest I'd go is around 6 hours.

High lights don't necessarily mean problems, they just mean things are more prone to them. If you watch your tank carefully and don't frequently change other parameters you shouldn't have a problem.

Also, he is just going away for the weekend :)
 

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You will still have positive net photosynthesis even with 2 hours, and even if you did not its two days you wont lose that much in two days. I do not run high light for longer than 3 hours a day and i have to trim weekly, i use 1wpg on a 20 (Super low light) for viewing only. Niko has success with this too i believe. Our plants are most likely C4 plants, which use pep carboxylase instead of rubisco.... their affinity for Co2 is much greater than a lot of the terrestrial plants.
 

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PPS-Pro, like the Seachem regimen, is lean dosing. For PPS-Pro, Edward advises for a 2-3 day absence to just fertilize as normal before you go and have the lights on for the normal photoperiod while you're gone. I was just away for 3 days and followed his advice and everything looks as it did before I left (with a little growth). I had no problems with not dosing for 3 days. I have only 2.3 wpg T5HO light though.
 

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Yup, it is only 2 days, so I suspect no matter what course of action he chooses to do it won't harm the plants or tank (even with lights on for 48 hours) :)

Also, C4 plants really only pull ahead of C3 plants when the temperature is high as well. Otherwise C3 plants are still more efficient than C4 plants at lower temperatures in side by side comparisons.
 

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Untrue...
Pep carboxylase is the enzyme C4 use to fixate carbon from Co2 in the stomata... It his a much much higher affinity for Co2 than Rubisco (C3 plant) this has nothing to do with temperature and is the defining difference between the two.

A c4 plant is typically a tropical plant, which may be why you said that. But the only way to make a C3 equal to C4 in high light conditions would be to greatly alter the co2 concentration so that O2 was so minimal it could not bind to Rubisco. Even then the C4 plant has many more physiological differences that makes it more efficient.

The two types of fixations are pretty much equal until you start reaching higher and higher light, where the C4 gets the advantage. Because photorespiration is so low it will fixate more Carbon and its maximum photosynthetic rate will be much higher. Hence high light for 2 hours will be sufficient to have a positive net gain in carbons with high light.
 

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In high light or high temperature C3 plants undergo photorespiration, which essentially is a deviation from the normal RuBp+CO2+H2O --> 2PGA --> calvin cycle because carboxylase (the normal enzyme that fixes CO2 into the calvin cycle) doesn't work.

When photorespiration occurs an O2 molecule reacts with the RuBp with the help of the oxygenase enzyme to create CO2 (which is lost), and 1PGA molecule that is fed into the calvin cycle. Since CO2 is lost in this reaction it is called photorespiration. Ultimately it is this CO2 loss that makes C3 plants bad in high light+high temperature environments.

C4 plants get around this problem by converting carbon to malate, then a CO2 molecules is split off the malate and fed into the calvin cycle. This prevents photorespiration and the loss of carbon from the system, making C4 plants efficient in high light + high temperature environments.

While it is true that C4 plants are more efficient at taking up CO2 than C3 plants this does not mean they will grow better than C3 plants under all conditions. CO2 uptake in C3 and C4 plants depends upon light, CO2 concentration and temperature. Each type of plant does better in its respective environment. C4 plants produce more sugar than C3 plants when the temperature increases and the light increases. But when the light intensity is decreased and the temperature decreases C3 plants produce more sugar due to increased photosynthesis. See graph below.



In addition, there are 2 points that each plant has with respect to growth. One is called the light compensation point (LCP), and the other is called the temperature compensation point (TCP). The LCP is the point at which the amount of light provided lets the plant photosynthesize exactly enough to live, but not to grow or reproduce. This point is where photosynthesis exactly equals the rate of respiration. The other point is related to the fact that for every 10 degrees Celsius change in temperature respiration (sugar breakdown+O2 usage) increases by a factor of 2. Therefore, the temperature compensation point is the point at which respiration has risen to a point that exactly equals the declining photosynthesis reactions (because as temperature increases near the protein's maximum limit it causes them to denature and they aren't as efficient). Anyway, what this all means is that each type of plant C4, and C3 has a different temperature and light compensation point, so under the same conditions a C3 plant will be more or less efficient than a C4 plant depending on what the conditions are (i.e. C4 plants have higher light and temperature limits, than C3, but C3 plants are more efficient at lower light and temperatures). See below



On land, I know that C4 plants on land don't start growing faster when more CO2 is added to the tank because they have smaller and fewer pores on the surface of the leaf. They have these traits because it helps them cut down on water loss in dry, hot, high light environments (it also helps them recycle CO2 from their own respiration processes). Now this may not be the case with aquatic C4 plants because they absorb CO2 through tissue contact with the water and don't need to absorb it through their pores like C4 land plants, but it is interesting nonetheless.

Also just for interest sake I'll list some advantages/disadvantages and facts about C3 and C4 plants that I know below:
1) Low light + low temperature C3 plants = more suited
2) High temp + high light C4 plants = more suited
3) C3 photosynthesizes more with more CO2 (at least on land)
4) Some C4 plants have reduced light reactions to prevent damage to the photosynthetic mechanism in strong light
5) Not all C4 plants operate at the same photosynthetic level
6) C4 plants are able to utilize the CO2 from their respiration processes more efficiently than C3 because of reduced stomate size and number.

I hope this clarifies what I was trying to summarize before :)
 

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Zapins your confusing C4 with CAM Plants i think. CAM plants have fewer stomates and adapt to dry regions. C4 are usually tropical... C4 plants are more efficient not because of the # or size of stomata but because of their method of carbon uptake. Rubisco in c4 plants is held within the bundle sheath cells (not stomata), keeping rubisco away from Oxygen is how they gain an advantage over C3 plants. C3 plants cap off earlier than c4 plants in regards to light levels for that reason.

Also all that information is great, but i was thinking about this earlier and it doesn't apply to the poster because we're underwater. I wasn't thinking through when i talked about c4 plants because photorespiration is reduced O2 levels are lower in water and co2 levels are artificially higher.

Also the temperature thing... yes protein degradation would be a problem and there might be a difference but i am talking about being practical here. Our fishtanks at 70-80 degrees... TONS of c3 as well as C4 plants grow optimally in these conditions. it really wont matter anywhere near as much as light levels.

I think we would be best to carry on any further conversation through PM on this subject because its taking away from the guys thread. I actually just complete a Plant physiology course where we discussed this subject, i am very interested in plant physiology and would love to talk about it. just don't want to hijack thread.
 

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Discussion Starter · #20 ·
Hey everyone, I am home now and all the plants are fine. I left my lights on their 10 hr timer and dosed a little heavy before i left and all is fine.
By the way I am a she not a he :)
 
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