# blue-green and hair algae help



## elifish (Jan 26, 2010)

I'm new at online forums, and have read all I can find about blue-green algae and hair algae but am still confused. At first I had bad hair algae; I reduced the light a lot, but the plants weren't doing well. I read that a break in the light cycle would help, but all that happened was that now I have blue-green algae too! I've been removing both manually and doing twice-weekly water changes, but both are getting worse, and I'm discouraged.

My water (Brooklyn, NY tap water) is so soft I can't figure out how to read the CO2 chart, so I don't know how my DIY CO2 is doing. I can't afford any expensive equipment. I ordered erythromycin. Do I need to do anything to the filter or light cycle during the dosing period? And I want to make sure the BGA doesn't come back! 
Wasserpest;951778 said "Dosing Nitrates should help to keep BGA away, as well as good circulation and regular water changes."
How do you dose nitrates? Mine are pretty low. My LFS advised me to only feed the fish sparingly every other day to help with the hair algae, because hair algae needs nitrates. I was using aquariumplants.com's "total substrate pellets" once a month till about 6 weeks ago when I was trying to reduce nutrients to help with the hair algae. I don't quite understand the nutrient/algae/chemistry thing.

Any advice would be greatly appreciated!

-30 gallon planted tank, set up for 5 months
-T-5 Fixture 2x39W 10K/460NM, 9 hours of light a day (on 4 hours, off 4 hours, on 5 hours)
-whisper power filter with phos-zorb in one side and ceramic rings in the other side
-DIY CO2, diffused with a tiny filter
-airstone
5 harlequin rasboras
3 white clouds
3 black phantom tetras
2 otos
Java ferns, anubias, crypts, anacharis, banana plant, small sword plant, 4-leaf clover, dwarf sag, bolbitus fern
ph 6.6, nitrites and ammonia 0, nitrates low (well below the color on my chart that says 12.5 mg/l), GH 2, KH 1.


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## Darkblade48 (Jan 4, 2008)

You have quite a bit of light for a 30 gallon tank. 

You cannot use the pH/kH/CO2 relationship to determine the amount of CO2 in your aquarium. This is because the relationship is based on the assumption that you only carbonate buffers in your water (which is not the case in an aquarium). As a result, this relationship cannot be used. In order to accurately check your CO2 levels, you will need to use a drop checker with a known dkH reference solution. Many people use a 4 dkH reference solution for this. You may not have enough CO2 in your tank, resulting in some of your algae problems.

Erythromycin will kill off the cyanobacteria, but to prevent it from coming back, you will need to take care of the root causes of the algae in the first place (i.e. low nitrates, inconsistent/low CO2, insufficient flow, etc).

Nitrates, along with phosphates, are important nutrients for plants in the aquarium. In a highly lit tank such as yours, the demand for nutrients by plants will be quite high, necessitating the addition of these nutrients. Plants require nutrients, light and CO2 in order to do well. If there is an imbalance between these, then the plants will suffer, and algae will be able to take over, as in your case. 

It is a common misconception that nitrates and phosphates are "bad" in the aquarium, but this is not the case.

In order to dose them, you can use commercial products such as Seachem Potassium, Seachem Nitrogen, Seachem Phosphorus and also a good micronutrients mix (Seachem makes this as well). However, this is definitely an expensive way to go, and uneconomical. The best way is to buy the bulk chemicals and dose accordingly (i.e. there are various dosing regimens out there; the majority of people with high light tanks use the "Estimative Index" (EI) method of dosing).


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## elifish (Jan 26, 2010)

Wow, thank you so much for the detailed reply! I have so much to learn. I now know what a drop checker is, and have checked out the EI dosing method, which seems daunting, especially the 50% water change once a week. Using this system, how do you know which nutrients to adjust? I couldn't locate a chart showing which nutrient to adjust for what result. Please don't tell me I need yet another set of test kits to test for all these nutrients!

Do I have more light than I need for the plants I have (either in wattage or in hours per day)? I thought I had between 2 and 3 watts per gallon.


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## Darkblade48 (Jan 4, 2008)

The best part about EI dosing is that in general, testing is not required. Perhaps the occasional test to ensure that all the levels are alright, but other than that, it generally does not require testing. 

This is because EI dosing works on the principle that you are providing more than enough nutrients for the plants, and the 50% Water changes conducted every week help reset the levels to prevent them from accumulating to dangerous levels.

As for your plants, most of them are low light or low light tolerant plants, so you actually have more than enough light (both in terms of amount and duration) for them. If possible, you could just use one of the bulbs (this may not be possible; it depends on how your lights are wired). Alternatively, raising the distance from the lights to the aquarium will also decrease the amount of light entering the tank.

With high light, comes the fact that plants will grow faster. As a result, there will be more demand for CO2 and nutrients. If you do not want to go this route, I would suggest lowering the amount of light you have.

On a final note, the "small" sword plant you have now will soon outgrow your 30 gallon tank.


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## MarkMc (Apr 27, 2007)

elifish said:


> Wow, thank you so much for the detailed reply! I have so much to learn. I now know what a drop checker is, and have checked out the EI dosing method, which seems daunting, especially the 50% water change once a week. Using this system, how do you know which nutrients to adjust? I couldn't locate a chart showing which nutrient to adjust for what result. Please don't tell me I need yet another set of test kits to test for all these nutrients!
> 
> Do I have more light than I need for the plants I have (either in wattage or in hours per day)? I thought I had between 2 and 3 watts per gallon.


T-5 lighting is very bright. One light would work ok 2 is too much. Try 7-8 hours. Remove the phosphate remover from the filter-phosphate won't cause algae-you actually need to ADD some along with nitrate, potassium and trace elements. You don't need test kits-EI operates on the principle of always having adequate levels of NPK/trace and then removing 50% of them (50% water change) to prevent build-up of excess fertilizers then starting all over. Having too much nitrate or phosphate or whatever is not the problem-it's not enough CO2 for how fast the plant engine is being driven by light-reduce lighting and you reduce the need for CO2 which makes it easier to have ENOUGH CO2 which is the root cause. Let off the throttle (light) and you reduce the demand for gas (CO2)-too much coolant/engine oil (fertilizers/traces) is not causing the lean miss-fire it's the lack of fuel (CO2).
I know, not a completely accurate analogy but you get the idea.


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## elifish (Jan 26, 2010)

Thank you! I'm beginning to understand the EI method, and am going to try it. I'm also going to put on the legs that came with the T5 lights, to raise them up above the tank. (In the previous incarnation of my tank, I had Tanganyikan cichlids that could really jump, but I guess my current fish won't.) I've ordered a drop checker too.


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## elifish (Jan 26, 2010)

*better diffuser?*

My blue-green and hair algae are gone, but things are still not going well. I raised my T5 lighting up above the tank on the little legs that came with the unit, and in the process one of the 2 bulbs quit working - so I probably don't have too much light any more. I got a drop checker, which has stayed blue; I tested my DIY CO2 for leaks using soap bubbles, and it seems fine. I was using a Hagen mini elite filter for a diffuser (a later model, slightly differnt inside, and all I could find, which never seemed to be diffusing well) until a few weeks ago when it started making a loud noise, then died. Right now I have an airstone below the uptake for my whisper power filter, but the large CO2 bubbles still go right to the surface of the tank and pop. I was using the EI dosing method, but it seemed like way too much food for the amount of CO2 and light I have; I tested for nitrates and they were way up there. I'm currently dosing about half the recommended nutrients for a 30 gallon tank, and changing half the water weekly. My plants just aren't growing! I've been looking for a better diffuser without any luck. I've been told that ceramic diffusers usually don't work well with DIY CO2 because it doesn't create enough pressure. Do I correctly assume that the low CO2 is the unbalanced part of my equation? Any advice on a diffuser would be much appreciated! My budget is small. Thanks!


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## MarkMc (Apr 27, 2007)

Yes, the unbalanced part is CO2. You could try making an in-tank reactor with clear plastic pipe (like the gravel cleaning siphon hoses have) and a power head. I recall seeing a thread somewhere here where it was done. I think they were very successful and it was cheap to make. Diffusing with an air stone or ceramic diffuser is not very efficient.


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