CO2 sparks thread/string algae explosion

[danakin]

More light is most definitely NOT a positive here. You have to have a balance of light, CO2, and nutrients.

Think of it as baking a cake. You have to have a balance of flour, sugar, eggs, chocolate, etc. If you go hog-wild and add 12 eggs to one batch of cake mix, that's gonna be one crappy cake.

Same thing here. 96w of lights over a 10 gallon tank is your problem. To put it in perspective, I have only about 80w over my 40 gallon tank. Lower your light output to one or two bulbs. Dose ferts. Keep up the CO2.

[DeadlyMuffin]

I cranked the CO2 back up and reduced the light to one bulb. We'll see how it goes.

In the meantime, I'll see if I can find a fertilization scheme I like.

[DeadlyMuffin]

I always hate it when people don't update threads to say what happened, so.... it worked!

I left the CO2 high, reduced light to 1 T5 bulb (which slowed, but didn't stop the algae), and then I introduced more fish and started dosing Excel. I'm going to look into other fertilization schemes, but just these minor changes have made a huge difference.

Before


After

Yeah the glass is cleaner, but look at the substrate and on the plants themselves. Drastically reduced algae.

[Hardstuff]

Check your bulb spectrum. If its not even close to 6500k, you will be making an algae farm no matter what you do.
I have 2 X15 watt T8's over my 10 & it is totally thriving. The water is crystal clear with NO ALGAE on plants or glass. I run 1 bubble every 2 to 3 seconds with a high end diffuser. I run 2X 6500k bulbs . Algae will out perform your plants without correct lighting spectrum , CO2, dry ferts , all need to be balanced as well as good filter flow with some surface agitation. Some surface agitation does not mean hang on the back filter. Small ripples that allow some gas exchange.
Your nitrates need to stay above 10ppms & PO4 should not crash either. PO4 should hold between (.5 - 2ppms). Added K & Fe as well as trace with boron.
If you have high nitrates out of tap you could use or cut in R/O water to reduce in comming nitrates but nitrates should stay above 10ppms at least if not 15 or more ppms.
40 to 50% water change at the end of the week for a tank reset.
Final word. Your lights are probably the wrong spectrum & too strong , your CO2 dose is off or poor diffusion. You need to stay on track with NO2, PO4 & dose EI every week. If ph dose not drop into the acid range your not getting enough CO2 into the water. Keep nutrients up drop lighting a little & check the spectrum, dose EI. my 2 cents

[DeadlyMuffin]

Originally Posted by Hardstuff

Check your bulb spectrum. If its not even close to 6500k, you will be making an algae farm no matter what you do.
I have 2 X15 watt T8's over my 10 & it is totally thriving. The water is crystal clear with NO ALGAE on plants or glass. I run 1 bubble every 2 to 3 seconds with a high end diffuser. I run 2X 6500k bulbs . Algae will out perform your plants without correct lighting spectrum , CO2, dry ferts , all need to be balanced as well as good filter flow with some surface agitation. Some surface agitation does not mean hang on the back filter. Small ripples that allow some gas exchange.
Your nitrates need to stay above 10ppms & PO4 should not crash either. PO4 should hold between (.5 - 2ppms). Added K & Fe as well as trace with boron.
If you have high nitrates out of tap you could use or cut in R/O water to reduce in comming nitrates but nitrates should stay above 10ppms at least if not 15 or more ppms.
40 to 50% water change at the end of the week for a tank reset.
Final word. Your lights are probably the wrong spectrum & too strong , your CO2 dose is off or poor diffusion. You need to stay on track with NO2, PO4 & dose EI every week. If ph dose not drop into the acid range your not getting enough CO2 into the water. Keep nutrients up drop lighting a little & check the spectrum, dose EI. my 2 cents

You should actually read my post. The algae cleared up quite dramatically, and is only getting better. I was posting an update to say that I took the advice people gave and it worked.

A lot of your suggestions are great and I do appreciate them!. Increasing nutrients and dropping the light level a bit is exactly what I did.

A small quibble about the lights:
They're 24W T5s, and they're 10k bulbs. The plants seem to be going gangbusters under them. The problem was too much light and not enough nutrients (and it's been solved, I think!).

I'm new to planted tanks, and the nutrient balance and CO2 aspect of it is not something I'm familiar with. But I've run reef tanks for years, and I do know something about lighting. Running with lights other than 6500K does not mean algae blooms. Corals can (and do) photosynthesize just fine under much bluer light than 6500K, there's no reason your plants can't photosynthesize under that light too.

What's important is PAR: http://en.wikipedia.org/wiki/Photosy...tive_radiation The graphs on that page should give you some idea of what spectrums work best for photosynthesis.

I'm not saying there's anything wrong with 6500K lights, but it's not the only option.