Blue-green algae

[Flux]

Hi I have an imbalance of phosphates and nitrates.I am aiming for 15 nitrates and 0.25 phosphates. I have the correct amount of phosphate but I have read that I should black out my tank for a while but should I do this before the imbalance is fixed or after when readings are correct and for how long?

[Hoppy]

If you only have a little BGA it might be best to adjust your fertilizing - increase the nitrates considerably, make sure you have good water circulation where the algae is trying to grow, and clean out as much of it as you can by hand. You could use more phosphate too, by the way, if you have 2 watts per gallon or more and lots of plants.

[Lissette]

Yes, don't be afraid to add a little more po4.

How much light do you have over your tank? How bad is the BGA?

[fresh_lynny]

vacuum your substrate and remove as much of it as you can, then up the Nitrates! That will fix it before it gets out of hand. Then a blackout will be in order.

[Marilyn1998]

I have 30 nitrates and 5 phosphates. I have some of this algae growing on the top of my repens, about three inches below the spray bar of my XP3. I have 1.5 WPG. I have cleaned off the leaves twice in the last few days and vacummed. Are my ferts out of whack? How do I lower PO4?

[fresh_lynny]

You don't need to lower your PO4 with your Nitrates @ 30. You seem to have close proximity to water movement, so next question, are you near a window or is your photoperiod a little too long? I would prune off the top of your repens, keep your Nitrates up....

[Hoppy]

Marilyn, I'm assuming that you are testing to determine how much phosphate and nitrate you have in the tank? Unless you have carefully calibrated the test kits, you really can't rely on them. And, with only 1.5 watts per gallon, you need to adjust your dosing lower than the normal EI tables suggest. I don't see anything in your description about CO2 either. With no CO2, relatively low light, and with discus in the tank, I think you need to do a lot of reading here and in other forums to see what will work best for you. Just using EI doesn't seem to me to be the way to go. (But, to answer your specific question, the plants should be using up the PO4 you have, so it should decrease unless you are dosing too much of it.)

[Marilyn1998]

Newby,

My room is very bright. I have large windows that face west, so I have to keep the blinds drawn. THere are also two skylights. My lights run 10 hours on a timer.

Hoppy,

I use Excel. I just dumped the PMDD idea yesterday. I am trying something new, so I am really interested in getting this under control.
I am using CSMB and K2SO4 both at 1/4 tsp once a week on Saturday. And once a week (Sun) dosing macros at 1/2 tsp KNO3, 1/8 tsp KH2PO4, 1/8 tsp MgSO4.
Every day but WC day I am dosing 2 caps of excel. So far, tho, today is the first day of this regimen.

I am only using test kits to get a feel for the dosing until I am sure I have balanced out everything.

[Flux]

Originally Posted by Lissette

Yes, don't be afraid to add a little more po4.

How much light do you have over your tank? How bad is the BGA?

I have a 36'' 'aqua glow' bulb by Hagen. I leave it on for about 10 hours a day.I get loads of the algae when I siphon the gravel.By the way I have about 30 nitrates and 0.25 phosphates now.

[Flux]

Originally Posted by fresh_newby

vacuum your substrate and remove as much of it as you can, then up the Nitrates! That will fix it before it gets out of hand. Then a blackout will be in order.

How long should I do a blackout for and am I doing it to kill the growth of the algae?

[fresh_lynny]

Originally Posted by Marilyn1998

Newby,

My room is very bright. I have large windows that face west, so I have to keep the blinds drawn. THere are also two skylights. My lights run 10 hours on a timer.

Hoppy,

I use Excel. I just dumped the PMDD idea yesterday. I am trying something new, so I am really interested in getting this under control.
I am using CSMB and K2SO4 both at 1/4 tsp once a week on Saturday. And once a week (Sun) dosing macros at 1/2 tsp KNO3, 1/8 tsp KH2PO4, 1/8 tsp MgSO4.
Every day but WC day I am dosing 2 caps of excel. So far, tho, today is the first day of this regimen.

I am only using test kits to get a feel for the dosing until I am sure I have balanced out everything.

Even though you only have 1.5wpg, you have a long photoperiod and with the windows and skylights, you are introducing more than 1.5wpg, so my guess is that macors <NO3 in particular> dosage may not be enough. I would dose 3/4- to 1 tsp NO3 for a 90 gal tank.NO2 deficiency allows the BGA to take hold. Prune aggressively, stir up and clean substrate and dose Nitrates religiously.

[fresh_lynny]

Originally Posted by Flux

How long should I do a blackout for and am I doing it to kill the growth of the algae?

OK if you are in need for doing a blackout this is how you should go about it.
First, clean out all visible BGA, prune, vacuum subtrate, and clean out the hoses and filter thoroughly. Then you need to dose Nitrates well. Them cover your tank with large black trashbags. I used packing tape to cover it with the bags, and don't forget to cover your hoses as well. You have to be thorough or it will not work. I even further covered it with a blanket. Obviously turn out all tank lights in the process. Your fish will be fine unfed for 3 days. They willeven get after some of the algae they were getting lazy with...No peeking!
Three days later, take off the plastic,feed your fish, do a 50% change and clean up all of the dead stuff you see, then dose Nitrates again! Give it a full 3 days of blackout, not 3 or 2.5 but 3-4. Once you dose your Nitrates again, resume your dosing as normal, but do not let your Nitrates fall behind again. I hope that helps. Let me know how it goes.
It sounds like you definitely need a blackout by the siphoning volume of the algae.
The purpose is to kill all of the algae <it is really a photosynthetic bacterium> and stop the lifecycle so you can get enough Nitrates going to prevent further regeneration. After the blackout, you should have no sign of it, and you can get ahead of it.