Nitrates and algal blooms...

J

joe schmoe

AC Members
Sep 20, 2000
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All things being equal, are the two directly related??

I've got a decent algal bloom going on. Not too much hair algae - maybe one or two leaves on my Java Ferns and on the front glass where it's easily removed.

My puzzle is that I have nearly NO Nitrates (mayyyybe 2.5PPM). I haven't changed any water in 12 days (vacation). I have a decent-sized fish load and I feel like I'm overfeeding.

Changes made just prior to algal bloom: +8 fish, +2 pieces of African wood for the Java Ferns rather than being planted in the sand, +two VERY large Anubias (I have NO idea which species) and I added a bunch of artificial plants (things were looking a little sparse). The plants had some dried algae on them from the previous tank...but I gave them a good hose-down.

A search told me my photoperiod was too long. It was 12 hours, so I just chaged the timer to allow a 9 hour photoperiod.






Is the bloom ONLY a result of the incorrect photoperiod?? Can this be a result of a lack of trace minerals from something like Flourish??

Click the link in my sig for tank specs and a pic taken tonight. As always...thanks for the newbie help.
 
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I think from what Ive gathered here and my own algea nightmares, you need alot more plants. Im sure others will reply. Read all these threads there is wealth of info here. Tim
 
I personally don't think its your photoperiod thats causing your algae bloom. My plant tanks have their lights on from 9am till 9pm everyday, and they're clear of algae.

We need more info on your tank. How many watts of lighting do you have? What is the size of your tank? Are you supplementing with CO2? What is your nutrient dosing routine (if you have one)?

-Richer
 
No CO2, low light, low tech...see the tank profile for details :D. As for nutrients, I've dosed Flourish iron according to the directions on the bottle for the first time a few weeks ago...then a corresponding amount after the last water change 12 days ago. I've dosed either 10 or 15ml of Flourish roughly once a week...more or less following the directions on the bottle.

I'm still aiming to keep this a low-maintenance tank and to not go too overboard with nutrients/ferts/CO2.

Here's the URL to the profile in case you have sigs turned off: http://www.aquariacentral.com/forums/showthread.php?s=&threadid=16126
 
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You make no mention of dosing anything but Traces, and extra Fe.
This will cause problems due to unbalanced fertilization.
Your 1.5watts/gal. is going to be a bit misleading due to the fact that it's CF which will act like closer to 2.5watts/gal.
You need to do water-changes more frequently, without 12 day gaps.
I agree with 750t about the amount of plants. With that lighting you need more stems and floaters.
This is, to my recollection, still a brand new set-up. Your bio-filter is immature and needs time to develop. In the meantime you need to get more plants and get them growing well. It's a bit tougher for them to compete without CO2.
I would compensate for that with more plants and as I said, some floaters to shade it. Water sprite and salvinia work great.

Back to the ferts. I would get a PO4 test kit and find out what you've got in the tank. Heavy feeding and inconsistent water changes can/will cause levels of many elements to get too high.
Lose the Fe for a while. It's only going to cause problems at this point. Get some K (in the supermarket as "No Salt/Nu Salt"). Start dosing that lightly (1/4 tsp. per 50 gal.) after WEEKLY-50% water change. Start dosing K AFTER getting more plants.
Test N and P. N should be at 5ppm and P should be at 0.5ppm. The Flourish you are dosing would be a good level if you had many, many more plants. I would cut back on that until you get them.
In short, the problem is that you have very good light, you are dosing an unbalanced amount of ferts, and you have very few plants to use the light and ferts........you're feeding the algae.
You have "green water". A blackout will get rid of it, but it will come back rapidly without the WCs and addressing the above issues.

Len
 
Correct me if I'm wrong, but I thought water changes were, for the most part, to remove Nitrates...the end result of the biological cycle. What is the purpose of frequent (yes, weekly is frequent) water changes if Nitrates are nearly non-existant?? Besides physically removing the waterbourne algae, what am I acomplishing by changing 50% of the water every week??
 
Originally posted by joe schmoe
Correct me if I'm wrong, but I thought water changes were, for the most part, to remove Nitrates...the end result of the biological cycle.
Click to expand...

Not on plant tanks. You actually want a small level of nitrAtes in a plant tank as a fertilizer. On every other kind of tank, yes, frequent water changes will indeed lower nitrAte levels.

What is the purpose of frequent (yes, weekly is frequent) water changes if Nitrates are nearly non-existant?? Besides physically removing the waterbourne algae, what am I acomplishing by changing 50% of the water every week??
Click to expand...

You're making a "reset" of your tank's ferts, so that you can establish a regular routine of fertilization and clean water.
 
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Originally posted by Timmain42
You're making a "reset" of your tank's ferts, so that you can establish a regular routine of fertilization and clean water.
Click to expand...

Hmmm. Seems like a waste to take out what I have to dose just for the sake of routine. There is no way to keep ferts/traces at acceptable levels without water changes?? There must be some other reason.
 
Originally posted by joe schmoe
There must be some other reason.
Click to expand...

Reason #1: Because it works?

I'm sure with enough experimentation and frustration you could find another path that works, but this (the aforementioned Barr Method) works right out of the proverbial box.

And don't feel bad. I have to change out the entire volume of -your- tank for my weekly water changes. And I too live in a place where water is at a premium... but man do those plants grow. :)
 
First of all, as previously mentioned, you need more plants.
Then you need to find a balance. You do this by establishing a routine. Water-change, cleaning, pruning and re-fertilizing.
This keeps the combination of elements consistent. Many of us fertilize 2, 3, or more times a week because the amount of plants require the nutrients. However, by the end of the week there may be an over-abundance of certain nutrients. A water-change, as stated, re-sets the tank for the most part to it's original state.
By doing this and watching the tank's condition and the plant's growth we are free to tinker with dosages to optimize these conditions and keep the balance necessary to avoid the issues you are now experiencing.
Ideally, once you've learned the requirements of your tank, the plants will have used most of the nutrients you've given them during the week.
BTW, it's not always necessary to do a 50% change. I do one in my 40gal. because it has 3watts/gal. In a lower light situation I've found that MY 55 gal. with 1.5 watts/gal only needs 30% to keep the elements balanced. Other's tanks will be different than mine.
I have found that my tanks don't use nearly as much NO3 as they do PO4 only because of routinely testing and weekly re-setting.
I change the water in 4 tanks(a 10, a 40, and 2 55's) and add back all the nutrients they need in 45 Min's. It's not that difficult or time consuming.
Check the reaction of your fish after a weekly change and then tell me it's not worth it.

Len
 
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