Algae problems and how to deal with them

Discussion in 'Algae' started by Dolfan, Feb 14, 2015.

  1. Dolfan

    DolfanFishlore VIPMember

    Recently there has been an influx of questions involving algae issues and how to get rid of it. I figured it would be good to have some resources in one central location to help share some valuable info on algae. I would like to make this into an article once I fine tune it a bit.

    Algae identification -
    There are many forms of algae and knowing what you are dealing with will drastically help. Many forms of algae look very similar and get confused, and this leads to fixes and solutions that don't work. Remember algae can have a variety of appearances and colors, so do some research to narrow down what you are dealing with. Google search the algae you think you have and you will find a ton of images and info that will help as well. Here are few links that will help identify algae along with photos, causes, and solutions....

    Algae causes -

    Algae can be caused by a variety of issues. Different forms of algae are triggered by different things as well. Some common causes of many algae issues include.....

    > excessive light (both too bright and extended photo periods) - raise your light fixture, lower your photo period

    > low CO2 - add CO2 injection, use CO2 substitute like Seachem Excel, increase surface agitation in non CO2 injected tanks

    > CO2 fluctuation - do smaller percentage water changes, make sure your CO2 doesn't run out, increase surface agitation in non CO2 injected tanks

    > unbalanced nutrients - having unbalanced nutrients can also trigger algae.

    Algae prevention -
    Preventing algae is far better than treating it after the fact. There are a variety of ways to try to prevent algae from forming, or at least inhibit it to some degree. Below are some ways that I have researched and used with some degree of success.

    > Adjusting your lighting - Perhaps you have too much, or perhaps too little. You have to know what lighting you are working with. What color temperature is your light? Approx. PAR value? How long is your photo period? These are all questions that every aquarist should know. Around 6500k is best for color temp. PAR affects what type of tank you want to have whether it be non planted=low PAR, low light = low PAR, medium light = medium PAR, high light=high PAR. Here is a link to understanding PAR....

    Quite often, people have a light that is too bright for their needs or is left on too long, or not on a fixed timer schedule. Timers are cheap, use one, and it will vastly help you out.

    Raising your light fixture a few inches can help. It helps spread out the light, and lowers the PAR the deeper you go into the water. Here is a link to some easy risers I made to raise my Finnex LED fixtures a few inches (the same concept could be applied to many light fixtures)....

    Adjusting the photo period can help a lot as well. Diana Walstad (pioneer of the Walstad tank method) is a big advocate of 2 separate photo periods with a "siesta" in the middle. This helps the tank build back up some CO2 for the 2nd growth period, rather then a continuous 8-10 hour drain on the CO2 levels. I also like it as I get to view my tank at night more often when I'm home and have time. A sample schedule would be something like....

    9am-1pm lights on, 1pm-5pm lights off, 5pm-9pm lights on, 9pm to 9am following morning lights off.

    Adjust it to your needs if you think your tank/plants need more light you could do 2 five hour photo periods.

    > Adjusting your CO2 - I am a big advocate of low tech tanks that do not need CO2 injection. I feel I can get more stable levels of CO2 which help inhibit algae. You can also have a very lush tank with a great variety of colorful plants, all without the extra hassles of CO2 injection. It seems many algae are triggered by fluctuating CO2 rather than just overall lower CO2 levels. Using an air stone for surface agitation in non CO2 injected tanks helps the water maintain an equilibrium with the ambient air.

    If you use CO2, be sure to keep it stable. If you use DIY CO2, consider using 2 or 3 separate bottles and staggering them by one week apart. This way when one is running low and fizzling out, the other is going strong. If you use a CO2 tank and regulator system, be sure to use a drop checker and monitor your CO2 levels for consistency. If you are using CO2 injection a air stone is only suggested perhaps at night to help prevent excessive CO2 buildup and gassing your fish. During the day this would off gas your extra CO2 that you are wanting to keep in the water.

    > Adjusting your nutrients - Fish waste and fish food usually provide enough Nitrogen and Phosphorus for water column feeding plants, but they lack in Potassium and micro/trace elements. Using a product like Seachem Flourish Comprehensive is a good liquid fert, as it is low in Nitrogen and Phosphorus but higher in Potassium and the micro/trace elements, helping to balance things out. If you have root feeding plants then be sure to use some root tabs. If you have no plants then nutrients shouldn't be an issue, just do regular water changes. Here is a link to a thread where I explain the common Seachem Flourish line of fertilizers including Excel as they are a good starting point and easily obtainable for most....

    Algae treatment -
    Once you have algae it can be a battle. But you can win this battle with a few different tricks.

    > Manual removal
    - lightly scrub away any algae with a scraper, tooth brush, or even your finger. It's best to do this before a large water change, as any loose free floating algae spores will get removed in the outgoing water.

    > Chemical treatment - I am very opposed to most algae chemical treatments, they are frequently the cause of other issues including death of plants, fish, and especially inverts. Use at your own risk and read the labeling as well as do some research to make sure they are safe with your inhabitants.

    One chemical that I do use and recommend is Seachem Flourish Excel. It is a liquid CO2 substitute that also works as an algaecide, so it's doubly good for our algae eradication needs. Regular daily doses will help a lot, as well as spot treatment. I suggest sticking to the regular daily dosage of Seachem Excel and not using the larger initial dosage suggested on the bottle, as I think this is where problems can happen with certain plants and inverts. Also note that certain plants are sensitive to Excel (vals, anacharis, and others). This can be overcome by slowly acclimating them to using Excel by starting with a small dosage for a week, then 2nd week increasing slightly, then 3rd week increasing a bit, more then 4th week finally going to normal daily dosage.

    > Spot treatment - First off, turn all of your filters and air stones off, getting the water very still. Load up a normal daily dosage of Excel into a syringe. Slowly squirt the Excel onto a problem area. Let it sit for 15-20 minutes then turn everything back on. You will only be able to get to a small area every day, so keep repeating every day, moving to a new area until you have zapped all the algae. The algae will turn pink, red, or grey letting you know that you zapped it. This can also be done with small amount of hydrogen peroxide, which breaks down into just plain water very quickly, so it is relatively safe.

    Whole tank treatment - Here is a link that explains a whole tank treatment involving hydrogen peroxide then following with Excel. Be sure to read the entire thread as many people have successfully used it and have chimed in with their experiences and tips. I suggest only using the regular daily dosage of Excel afterwards, and not the larger initial Excel dosage recommended on the bottle. I have personally used this method a few times with fish, plants, and shrimp with good results.

    > Blackout - many forms of algae can be eradicated by a blackout for a few days. Do some research to make sure that this will be ok with any plants or fish you have. Putting a large blanket over the tank works, but also I would suggest an air stone to help make sure their is enough oxygen in the water.

    Overall tips and tricks that I have found very useful for dealing with algae -

    > Daily dosing with Excel or other brand liquid CO2 substitute

    > Split photo period with 4 hours "siesta" in between

    > Keeping plants, as they will outcompete the algae for nutrients. Suggested plants that are very helpful are anything that grows quickly, especially floaters like frogbit, hornwort, anacharis. These plants are known as nutrient sponges. Anyone can keep plants, they are easy, don't be scared, here is a link to another article I wrote about easy low tech / low light tanks....

    Also using floating plants helps shade the tank some, so limiting the light that penetrates deeper in tank for algae to grow.

    > Get a cleanup crew like nerites snails, amano shrimp, bristlenose plecos, red cherry shrimp, are all great helpers in dealing with algae. Be sure they are compatible with your setup and do not overstock your tank. Adding more problems to deal with later is not a good method of dealing with algae. Any of these "helpers" will not fix your problem, but they can be of assistance.

    > Trim any algae covered leaves or remove any algae covered décor. If you see the algae, get it out of there, as it will multiply quickly. The quicker you react at the first sign of algae, the easier the treatment will be.

    I hope this has helped out and spread some light on the algae issues that we all live with. Remember every tank has algae, it's just a matter of limiting it so it's not unsightly and out of control. Prevention is always better then treatment. And remember google is your best friend in this hobby, there is a ton of valuable info out on the web, you just have to find it. If your are still confused and need help by all means search the forum, odds are someone else has had a similar problem. If you still can't find any info post a new thread and be sure to include important info such as water parameters, tank size, inhabitants, light fixture info, and photos always help.

    Thanks for reading!
    Last edited by a moderator: Feb 14, 2015
  2. OP

    DolfanFishlore VIPMember

    Thanks for the kind words. Ideally I would like this to be an article and stickied. It seems the articles are hard to find for some people. Mike and the mods is it possible to have a "sticky" in each section that is something like "helpful plant links", "helpful maintenance links", etc for the respectful sections. This way we could post links to the articles that pertain to that section or other helpful info. I read a lot where people say they couldn't find an article or didn't see any info. We have a lot of helpful articles both on the front home page next to the light bulb icon "Aquarium Articles" and the "Articles" tab at the top of the page. The 2 separate areas makes it confusing also.

    Let me know if anyone thinks of info about algae I need to cover or add to this.

    On a side note, "Mike and the Mods" sounds like an excellent 80's cover band. I'm envisioning tight leopard pants, acid washed jeans, and a lot of long teased out rocker hair full of hair spray.
  3. ryanr

    ryanrModeratorModerator Member

    Great write up Dolfan :;hf
    Agree with most of it :)
    Totally agree - identifying the algae is the first thing to do. I'll also add my favourite link
    Umm, increasing surface agaitation will decrease CO2 content even more :;sh

    Depends on the algae. Excel is extremely good at eradicating BBA, not sure about other types of algae though.

    Be careful dosing Excel with shrimp, particularly RCS.

    And on the subject of cleanups - as pointed out, some fish can help reduce, but not eradicate algaes.
  4. OP

    DolfanFishlore VIPMember

    A few things....

    As for the surface agitation and CO2 content.... In non CO2 injected tanks it actually helps to keep the levels up a bit. Lets say normally the water reaches an equilibrium of 5ppm CO2. Plants will use up a lot of that CO2 and lower that number down to 0-3ppm. Surface agitation will help bring it back up to 5ppm which the water will naturally hold due to CO2 content in the ambient air around the tank.

    Now in CO2 injected tanks you artificially raise the CO2 content up to 20-30ppm CO2. So using an air stone to create surface agitation will bring it back down to the equilibrium zone of 5ppm CO2.

    Surface agitation just helps to bring the CO2 content back to it's normal amount of around 5ppm. Many people think that air stones and surface agitation decrease CO2, but this is only in CO2 injected tanks. The above numbers are just used as rough estimate to demonstrate my point.

    So in non CO2 injected tanks, without some extra surface agitation, the CO2 levels may stay too low, allowing algae to get a foot hold, and inhibiting plants growth. But with a little help and getting the numbers back up to the 5ppm range plants will do much better, and algae is somewhat inhibited.

    Here is a thread from discussing the surface agitation in non CO2 injected tanks....

    As for Excel and shrimp.... I have successfully used Excel with RCS and Ghost shrimp and done a lot of research on this, as I was a bit scared to at first. It seems that most of the bad results happen when people use the large initial dosage suggested on the Excel bottle. If you stick to the regular daily dosage you should have no problems. I know many people who have used it successfully and would agree. Like anything use caution and perhaps slowly work up to full dosage over a few weeks and see how your shrimp react.

    Seachem forums post... thread....
    Last edited: Feb 15, 2015
  5. Aquarist

    AquaristFishlore LegendMember

  6. OP

    DolfanFishlore VIPMember

    Aquarist - I just looked at this today and it does not appear to be "stickied". It wasn't too hard to find only being the 4th thread, but eventually it may slide down the list and become difficult. Thanks.
  7. Jswin

    JswinWell Known MemberMember

    Dolfan if the tank is in a room where all lights are off and curtains closed is the sheet over the tank necessary for a blackout?

    Sent from my iPhone using Fish Lore Aquarium Fish Forum
  8. OP

    DolfanFishlore VIPMember

    The blackout method, needs to be really dark. If you can get it pitch black in the room without using a cover over the tank, than you should be fine. But if you have any light coming through the curtains it could fuel the algae. Algae have adapted to be able to live in really rough conditions like very little light, or low CO2, it's what makes it tough to get rid of. But plants can survive the blackout for longer, so they can outlast algae.
  9. Fred Smallwood

    Fred SmallwoodNew MemberMember

    Yea, all I needed was more websites to look up? Why do you think I came here?
  10. FishandFun

    FishandFunValued MemberMember

    Thanks, very useful. :D
  11. Genobreaker

    GenobreakerWell Known MemberMember

    Interesting. Always thought bigger water changes would be better for stuff like bb. Been having an issue with a combo of bb and cladophora algae so hope this'll help in my ongoing war with them.
  12. Cricket lynn mclean

    Cricket lynn mcleanWell Known MemberMember

    So has anyone here tried the whole tank dosing from the thread linked? On a large tank specifically? It takes quite a bit longer to do a 50% water change in a 120. I read several comments on the planted tank but there's over 400 now and sheesh. One person in a very large tank had a lot of loss of life. The op said he would rethink it for larger aquariums but I didn't see it come up again or notice and edit. Thoughts on this? And is it safe for clown plecos? Lots of questions on snails and shrimp but I didn't notice any on plecos.
  13. Aquarista

    AquaristaNew MemberMember


    Thanks for the info above. I got into this hobby knowing I would rely on others for info. I don't have time to read up on everything. Often it is simpler to just ask.

    Can I post my simple algae problem here? My assessment concerns the presence of algae and duck weed along with a wisteria plant.

  14. Aquarista

    AquaristaNew MemberMember

    VICTORY, i resolved my algae problem in 24 hours thamks to your info....TY TY TY
  15. Dingdangma

    DingdangmaNew MemberMember

    Wow, thanks for the article. It's very informative, maybe too overwhelming for a beginner like me, but I will definitely know where to look for tips when dealing with this type of problem.