[from Gen. forums] Crazy algae problem! (please help ASAP)

[cgcaver]

I have a planted 55g with 2wpg on the plants and a AC500 doing the dirty work. I have an 5" oscar, 5" pleco, 7" ropefish. I leave the lights on for 8-10 hours a day. I do a weekly water 75%-80% water change, and at that time change the floss, and rinse the sponge/biomax. I have Flourish root-tabs in the sand for my plants, and when I do a weekly water change, I usually treat the water with a little Fe, K, Flourish, and Flourish Excel. My current water parems are:

7.6 PH
0 NH4
0 NO2
20ppm-30ppm NO3
1.5ppm PO4

This is about 6 days past my last water change (which i planned on doing tomorrow).


So, here's my problem: a mere 2-3 days after I do my water change, my water begins to get pretty cloudy. Its mostly a whitish color if I look at it hard enough, then a day or two later it turns into more of a greenish color if I had to describe it. Towards the 4-5 day after the water change, I start to notice some green splotches on my glass. My pleco does a VERY good job of eating algae usually, so it doesn't ever get really really bad.

Now, here's my question. What the heck kinda algae is this? Why can't I ever get the "good" kinda like beard/carpet algae LOL. At least it can be controlled and looks natural. I have nice drift wood and porous statues in my water, why cant THEY ever get some good algae growth ?!?! Before you jump down my throat about the high bio-load, let me say this. My plants have always done a very good job of keeping my nitrates and phosphates down. I used to check my water religiously, and this problem really only started about a month ago. I know my nitrates and phosphates are a lil on the higher side, but is that REALLY whats causing these non-stop blooms?! Also, I've heard that adding some aquarium salt can help stop blooms... true? I dont wanna hurt my fish or plants :\ Also, I was wondering if dosing something more would help? But then I was afraid I was dosing too much stuff... I was wondering if potassium was my limiting nutrient on my plants, and if I added more of it, they may be able to "choke" the algae outta the water...?

Can you guys please help? I'll be glad to provide any other info needed. Im so sick of only getting to enjoy clear water for 1-2 days max after a water change. My tank looks like poop!

 

[travis simonson]

That's an interesting problem. I agree that your nutrient levels are a bit high, but not likely to cause serious algae problems. I would try supplementing with Potassium sulfate (you can buy it at www.gregwatson.com). I add 10-20 ppm to my tank during my weekly water change and forget about it. If that doesn't help out within a few weeks I would try limiting your nutrients to NO3: 10-15 ppm and PO4: .5 ppm. Your plants may be absorbing all of the nutrients they need from the substrate/plant tabs and leaving much of the nutrients in the water column to algae.

As far as adding salt, I would not recommend it. It is not good for your plants nor (if you've got any) your snails. I don't think it would have any effect on your current situation.

Hope this helps

 

[Guest]

a weekely 75-80% water change seems like an awful lot to me! i do weekley 20-30% water changes.

 

[malkore]

I like a weekly 50% change. However he does have some messy, large fish in that tank, so I could see 75% w/c being a good thing for his fishes health.