Green water, heavily planted tank

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NowherMan6

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I know there are a ton of green water threads on here (believe me, I've done my research) but none of them seem to fit my situation - most seem to be about unplanted or lightly planted tanks. How does one clear up green water in a heavily planted tank?

The green water in my tank set in about a week ago after I did a major pruning job. I get the feeling that that's what may have upset the balance in my tank... I fertilized and dosed nitrates enough for the plants I had, but didn't compensate when I took about half of them out. Now the tank looks like pea soup.

To combat green water, everyone always says to reduce the amount of nutrients in the water column and reduce the duration and intensity of light - and then the other commom adage is to "get the plants growing to outcompete the algae." So do you see the contradiction here when it comes to a planted tank? How am I supposed to grow the plants when I cant add nutrients into the water? Or when I lower the intensity of their light, and turn off their CO2 because of the lower light levels?

So this is what I'm thinking: I'm going to invest in a diatom filter just to initially clean up the water. Once that's done, add some hornwort or wisteria to get a nutrient eater in there, and start fert dosing as I normally would.

Will this work, or is there another way I should do this after filtering the water? Thanks.
 
You pretty much answered your own question. You decreased the plant mass and didn't compensate with a lower dosage of nutrients.
Basically, the way to clean things up is to keep the light at the same wattage, run the CO2 at optimum level and 1/2 the nutrients. This keeps the plants growing and using the available nutrients.
When the algae recedes, increase dosages incrementally as needed to maintain balance.
Tanks constantly change regarding need and we must observe and tweak dosages to compensate. Light and CO2 remain the same.

Len
 
so you're saying I should still dose nitrates and traces? isn't that counterintuitive though? isn't that just like adding fuel to the fire?
 
You have an over-abundance of nutrients in the tank, relative to what the plants are using, causing an excess of one or more of your nutrients.
To correct this you need to remove the excess, but still keep the plants growing well.
Try to estimate how much of the mass you've removed and alter your dosages accordingly.
In my tanks(and trust me this has happened to me when my brain has locked:)), I have cut dosages of Macros and Micros to zero for a few days, leaving the lighting and CO2 alone. The plants have stores of nutrients built in and will grow well for a few days to a week. Then resume dosing at 1/4 - 1/2 and increase as mass builds again.
The biggest ally for algae is poorly growing plants. Keep them growing well and seek the balance you achieved before you pruned.

Len
 
My experience and most of what I've heard has always been that once the green water starts you will have to kill it to stop it. The adjustments and other suggestions will prevent it's return, but no matter what you do right now it will remain. I may be incorrect, and Len definately knows much much more than I do. But you will need a blackout to kill the alge bloom in the water column, and then adjust things to prevent another bloom later.
Dave
 
Go with Lens advice! But you will still need to remove the algae...a diatom filter is a good option. IME a blackout for this stuff really never quite does it.

During maint. use paper towels on the glass and throw them away...you will be happy with the result but it will be a week or two from now.
 
Generally folks get GW from NH4 excess at some point.
Once the algae bloom, it's therre and you are not able to power the nutrients to get rid of it, nor starve the nutrients to get rid of(this latter method does not work BTW for any algae I know of).

You need to kill/remove what's there.
They are 2-5 microns in diameter.
So Diatom, UV or a micron filter will remove them.

GW generally does not come back unless: poor CO2+ high light, NH4(even a little), you use Jobes sticks in the substrate and pull things up every so often(these have NH4), do not have enough biological media or a very undersized filter etc(goes back to the NH4 issue)

The spores need the NH4.
The adults are very tough and need removed via a mechical or UV type of method.

Dose like you normally would during treatment.
GW can survive on next to nothing, you will not solve the issue by limiting them because, simply, they are never limited in a planted tank.

Your plants will die before the GW goes away.

Think about it this way, 1000 mice, 1 elephant, limited food source they both can eat. Who will be the last one left?

Regards,
Tom Barr
 
I recovered from a GW episode about four months ago. We're talking fluorescent pea soup green. The cause: a couple of dead SAEs which caused a nitrate spike followed by an ill-advised large dose of potassium. I concur with the advice above. I did a five day black out period (didn't bother with towels, etc, just no lights) with daily 50% water changes. Switched to a Magnum HOT micron filter to clean up what was left. (You might also try those micron filter cartridges that fit on the intake of powerheads.) Resumed normal fertilization and water changes thereafter. Result: crystal clear water, incredible plant growth, and a tank that looks better than it has in years.

Before you pitch your green water, find out if anyone is raising daphnia. Green water is as good as gold in those circles.

WMC
 
Thanks everyone. That's pretty much what I was planning on doing anyway.

I ordered a diatom filter and I'm going to use that to clear out what's there now - once I clear up the water I'll make adjustments to my ferts and hopefully get everything under control again. The plants are still growing quite fast (at least the ones I can see), though they aren't pearling nearly as much as they used to. CO2 is at a good level.

Truth be told - and I'm kind of ashamed to admit this - when I first planted my tank I used root tabs and I'm thinking they may be causing some of the trouble I've been having with algae. I've replanted and aquascaped several times since then, so those tabs have gotten up into the water column a few times... :(

djlen, I know you preach against those things quite often - mostly for the reasons I just gave - and man are you right. Thanks again everyone, I'll update after about a week or so. Cheers!
 
Well it will not likely come back, mainly a new tank thing or a Jobes stick thing.

Adding the "dirt" from an estblished tank's gravel or filter and packing the tank good with plants from day one, prevents any such issues and obviously not using those cheap tabs with NH4 in them.

SAE's upon dying rot into NH4, not NO3(this occurs later), that's what caused the GW outbreak with WMC's tank.

I can add 30-75ppm of NO3 and not induce GW using KNO3 and that also would add ~20-60ppm of K+.

Obviously both are in far excess for GW, but upon adding a small amount of NH4, roughly 0.5ppm. Then I get greenwater.

Toss a jobes stick, a small piece even into the water column near some flow.
You'll soon find out what nutrient causes algae, it's not K, PO4, or NO3.

Regards,
Tom Barr
 
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