I just recently started dosing fertilizers to my 10g, non CO2 tank. I have 2 - 9watt 6500k bulbs and they have been on for 8 hours/day. I do 50% water changes every week. The algae that I had a terrible run in with in the past is back again. All the edges of the leaves of the plants have algae and it's growing with a little more vengeance on the tank walls. Undoubtedly this is partly due to the increased lighting that I have now (before starting to dose ferts, I only had one 13w bulb, 6 hours/day). So what I'm wondering is, is there anything that I'm NOT adding that I need to add, or anything I'm ADDING that I need to increase/decrease to give the plants more of the upper hand?


Also another problem, I bought a Vals and the edge of one leaf was kind of yellow when I bought it. It spread up the leaf so I cut the leaf off. Now many of the leaves are turning yellow on the tips and dying. What is this a symptom of?

Ack ! Edited in horror: I forgot about your low light limitations. Your choice of Val seems very appropriate under the circumstances. I have done this in micro systems, but I started with no less than 30 small Italian Val W/ 7 watts of light in a 2.5g hex (Presently a vigorous little jungle W/ little or no algae at all). I'd perhaps gently clean the algae off, and maybe give them a spritz of peroxide for a few minutes, and maybe increase the number of val,but stick with smaller varieties. I'd keep the nutrients a bit lean and fall back on fert plugs for the swords (Only if neccessary !) HTH, Prof M

First, stop doing the water changes. For non-CO2 tanks water changes mean fluctuations in CO2 content, and that tends to induce algae to start growing. You should be able to get Vals, especially, to grow without much trouble. Just dose about half the EI quantities and only once a week. For a ten gallon tank, your 18 watts of light is low light intensity, and probably alright for non-CO2 and non-light demanding plants. Everything will happen slowly with that kind of tank.

Is the algae growing on the leaf edges black or green? Growing on the tank walls sounds like green dust algae. If it is that you could attack it by wiping down the walls and changing most of the water every day for several days in a row. It is hard to get rid of no matter how you try to do it. The other method is to ignore it for 3 weeks, let it grow until it changes color and thins out, indicating that it is at the end of its life cycle. Then wipe it all off, change most of the water and repeat the wipe down and water change every day for a few days. At worst, this would leave you with a lesser amount of algae to deal with. I found when I did this the plants thrived as the algae hid everything from view, so it was rewarding to finally wipe it off and see the results. But, that was with a higher light intensity too.

But, once you get that GDA under control, then stop doing the regular water changes. Just top off the water when evaporation losses require it.

I know in the past that if I held off on water changes, bga would just grow like crazy. But I can try going every two weeks for water changes and see what happens. Or should I stop completely?

Also I'm treading a fine line with water agitation. If I slack off with agitation, bga takes over. But too much agitation and I'm losing what co2 I may have. Right now I have one hob filter plus an internal corner filter (air powered). Both are in the same corner of the tank so agitation is high there but lower on the other half of the tank. Should I remove the corner filter and just try the hob by itself?

The algae on the tank walls is a lighter green color and it's kind of growing in streaks, you can see where I scraped it off before so it's growing back where I didn't get it totally clean last time. The algae on the plants is a dark color. It looks like black edging on the leaves. Also the algae is sprinkled over the faces of the leaves too in small dark green spots. It doesn't come off freely. It's attacking my Hygro and now my Vals. Maybe I will also try the peroxide thing. Does that work on bga?

If you are not injecting CO2 you won't lose CO2 with water agitation. You will pick up more, just as you pick up more O2 by agitating the water surface. So, that isn't a problem.

BGA seems to start when there is a lot of light and too little nitrate. If sunlight strikes the tank BGA almost always will start at those locations.

The algae on the glass sure seems like Green Dust Algae. And the spots on the leaves might be green spot algae, which generally means not enough phosphate.

Why not use Excel? In a 10 gallon tank Excel isn't terribly expensive, and by dosing at 1.5 times the recommended dosage you can kill off the black brush algae, if that is what is on the leaf edges, plus supply more carbon for the plants. And, you can increase the dosages of nitrate and phosphate a bit to see if that helps with the BGA and GSA. Using Excel might make doing water changes a little less risky too.

If the algae on the glass is green dust algae - if it wipes off easily it most likely is - I still like the method of leaving the algae alone for 3 weeks to make it live out its life cycle, then wiping it off and doing heavy water changes for a few days.

Look at all of this as one more way to enjoy your hobby! What fun would it be if there was never anything to do?

"Why not use Excel" ?

Can't use Excel with Vals !!!

Well now, I guess I should have re-read the first post a little more carefully. That is a pretty good reason to bypass the Excel. On the other hand, I did use Excel with vals and while they all died back, they also all came back after I stopped using so much Excel. I suppose one could just develop an admiration for black edged leaves? Remember, some beautiful red plants are only red because they are stressed out.

Well...I don't recall the exact numbers, but I'm reasonably certain everyone has botched Excel dosing at least once, and a few of us have done it repeatedly ! LOL.

Now that I think about it, Many of my best show plants were either Diebacks or Runts at one time. Never write off a plant until it begins to smell Really Bad...

Funny you should mention red plants ??? I have one Italian Val set smack dab in the center of a field of at least 100/200 that has always been a lovely rose color. Go Figure ?

Ok. So I will try increasing the amount of phosphate I'm dosing and nitrate. I guess it all depends on what kind of algae I'm dealing with here. The stuff on the faces of the leaves I think is green spot algae. It doesn't come off easily or at all. The algae on the tank walls is lighter in color than what I have had in the past with bga, so it probably is green dust algae. It scrapes off easily with a credit card. What about the Vals leaves turning yellow? Or maybe this is normal when you replant it?

Actually I am looking into getting Excel, I went to the lfs yesterday and she's seeing if she can order it in for me. The reason I'm doing this though is because I'm setting up a new 32g next week and don't want to invest in co2 yet. By the way, any suggestions on the planting of a new tank, what I should get etc. would be great since I've never set up a tank of this size, planted, from scratch before. I'm ordering in a bunch of plants next week for it so I can basically order whatever I want and the lfs will bring it in. The tank has 40w of light.

40 watts of light will not be very effective on a 32 gallon tank. The first thing I would do is try to increase that to at least 55 watts, which can be done with an AH Supply kit. And, as much as I enjoy vals I wouldn't use them or Egeria Densa, since both are sensitive to Excel. If you do go to 55 watts with an AH Supply kit, you should be able to use almost all other plants, except those specifically needing very high lighting. The best plant guide I know of is at: http://www.aquaticplantcentral.com/f...c/plantfinder/.