# Dry Start Method Flooding Question Lighting Duration



## Attackturtle (Dec 30, 2016)

I have researched and am preparing a DSM on a 20 long. Several times I have seen references suggesting to CUT lighting time after the flood but I cannot find any reference as to why. I plan to pump CO2 like crazy but during the DSM, heavy lighting seems to be encouraged so why cut light? Is it to lower the plant photosynthesis? Is cutting the light not accepted by all as best practice?


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## mott (Nov 23, 2006)

One word... Algea


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## Attackturtle (Dec 30, 2016)

ugh .. well part of the reason to dsm is algae prevention. I don't recall a lower lighting period suggestion for normal plantings.


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## klibs (May 1, 2014)

the point of DSM is to blast it with light and grow things out quickly so that when you fill the tank everything is grown in. most people also use very long photoperiods of 12+ hours during dry start.

usually this level of lighting if far more than you should use after you fill the tank with water / you will get algae if you do not reduce it. in the open air plants have access to ample CO2, will not get algae on them, and can probably grow a lot faster / demand more light. once you fill with water you can run into issues (algae) if you run too much light vs this was never a concern during the dry start.

just be careful... the last thing you want to do is wait forever during dry start and then nuke your plants with light and get an algae explosion that ruins everything. this happens to quite a few people who attempt dry start.

IMO dry start is not worth it (most of the time) for this reason... if your tank is set up properly you can grow a carpet within a few months (if that) with good CO2 and care just fine underwater. also a lot of people screw up after dry start is complete and basically have just wasted months of their time. this is especially true if these people have no prior experience with the plants they are using in a submerged setup prior to doing dry start. if you have grow the plant successfully before you will have much less chance of screwing up once you fill the tank. if not, most people make the same mistakes they would have made anyways in the first place... just now they have wasted months of their time waiting for plants to grow out...

basically if you have never grown carpet plants submerged before you should probably not dry start for your first attempt. you say that part of doing a dry start is algae prevention... this is true because you will have a lot more initial plant mass which make it easier to avoid algae when starting out. BUT by doing a dry start you are not all of a sudden immune to issues down the road. IMO it is like CO2 in this regard... people usually overestimate the benefits and think they won't run into algae issues if they use it. it has many benefits (instant higher plant mass, usually a faster carpet, etc) but it also has many drawbacks (acclimation period of plants / melting after submersion, possibility of mold taking over, takes a long time, no guarantee of success once you fill the tank, etc). if you do it RIGHT then it is a great way to start a tank. many people just screw up after they fill the tank anyways though


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## Attackturtle (Dec 30, 2016)

klibs said:


> basically if you have never grown carpet plants submerged before you should probably not dry start for your first attempt. you say that part of doing a dry start is algae prevention... this is true because you will have a lot more initial plant mass which make it easier to avoid algae when starting out. BUT by doing a dry start you are not all of a sudden immune to issues down the road. IMO it is like CO2 in this regard... people usually overestimate the benefits and think they won't run into algae issues if they use it. it has many benefits (instant higher plant mass, usually a faster carpet, etc) but it also has many drawbacks (acclimation period of plants / melting after submersion, possibility of mold taking over, takes a long time, no guarantee of success once you fill the tank, etc). if you do it RIGHT then it is a great way to start a tank. many people just screw up after they fill the tank anyways though


Main goal is to allow carpeting plants time to root and fill in I only mentioned algae prevention when Mott said the lighting cut is for algae prevention. I am under no assumption I get to walk algae free and welcome the challenge. I am just trying to clarify why people go from a long, sometimes 20 hour lighting period down to less than 8. I understand and can handle blasting CO2 but I just don't get the lighting and how long to wait before the ramp back up to 10 or 12 hours. 

Just trying to get my plans laid out. This is a hobby of patience which I have as a virtue. I've been planning this tank since December. Only just got down to leak testing and choosing my hardscape.


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## Junelle (Oct 22, 2017)

The reason why people go from 20 hours of photoperiod to 8 after flooding is due to the fact that plants grow slower in a submerged stage as compared to when it was emerged. High light also contributes to algae blooms in flooded tanks, so that may explain why getting the photoperiod right when you flood the tank. It is best to cut down the light once you flood the tank while letting the plants acclimate to the submerged state before ramping it up again.


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