DIY co2 issue Question

Discussion in 'DIY - Do It Yourself' started by Algae Eater, Dec 28, 2009.

  1. Algae EaterWell Known MemberMember

    I just made a diy co2 "device" and it is causing a lot of "soapy" bubbles on the surface of my 10g tank. Does anybody know if this is OK? There is no leaking from the bottle into the tank that I can see. The device consists of a 2-liter soda bottle and a tube with a check valve and airstone at the end. I've heard that some people add a second bottle to catch any liquid that might get into the tank, maybe I'll add one, but like I said, I don't see any liquid leaking into the tank. Thanks!

  2. NutterFishlore VIPMember

    I always use the catchment bottle/sump on my diy set ups. Even if you don't think any liquid is getting through you should use the sump. You won't actually be able to see any fluid getting through as it is condensation in the line that comes through very slowly.

    The bubbles on the surface are because of the way you are diffusing the co2 gas most likely. The fine bubbles are getting caught in the surface tension of the water instead of just breaking through to the atmosphere. This is good & bad at the same time. It's good because it means that your bubbles are very fine & are rising through the water slowly. It's bad because if the bubbles on the surface are bad enough it can actually reduce the amount of light that penetrates through to your plants.

    Just a side note that bio-wheel filters are not very good in co2 enriched tanks. The surface disturbance they cause releases much of the added co2 gas. You will get some benefit from the addition of co2 but it's effects will be limited considerabley by this type of filter. CO2 enrichment works best with canister or internal filters.

  3. Algae EaterWell Known MemberMember

    Thank you for the info and the quick response! Condensation--duh! I should have thought of that! I went ahead and put a catchment bottle on. The soapy-looking bubbles were not so bad that they were affecting the lighting and they seem to have dissipated a lot but that may be because I messed with it. Just as long as it isn't yeast getting into the tank because I've heard that can kill fish!

    I can't really do much about the filter right now but I'll keep that side note in mind. I have a few weeks to figure something out before I transfer it to a 55g. I plan on making a DIY filter eventually. Thanks again! ~Chris

  4. hop2jrValued MemberMember

    Ya Chris the bottle (Bubble counter/gas seprater) is for 2 things will ok 3. 1 is so that you can count the bubbles to calculate the amount of CO2 going into the tank, 2 to seperate any bad stuff coming for the yeast mix, any liquid or hard gases get traped in that water( change everytime you change youre yeast mix), and 3 to know when the yeast mix needs changed by the bubble count slowing or stopping. hope this helps you understand the Bubble counter/Gas seperater a little better I would never run one without. Good luck with the 55gal
  5. NutterFishlore VIPMember

    Different item hop2jr. What Algae Eater & I were refering to is a dry sump purely to catch overflow from the co2 mix. You can make a bubble counter but the holes need to be in different places in the bottle & check valves are mandatory. There is also the strong possibility of water leaking if the seals are not perfect. It also doesn't help with any of the "hard gases", like you said. At least to my knowledge. Gas is gas. It is lighter than water & will simply travel through the water with the co2 gas & end up going to the tank anyway.
  6. roger dNew MemberMember

      make the best D.I.Y. co2 generater i've seen no holes drilled in the cap etc and a plant supply company aqua essentials supply what seems like a good diffuser which is part of a kit, where you get a small airosol of co2 gas, a check valve 1.5m of silicone tubing and of course the diffuser, all for £9.99. Once you have used up their gas, you can make a gas generater o your choosing and use that.
    Best of luck roger d. first post.
  7. Algae EaterWell Known MemberMember

    Thanks for the idea.   I've already gone through all the trouble of drilling holes in the cap(s), though!
  8. ctcleeValued MemberMember

    I had the same issue and I DO use the drop checker/bubble checker and i thought it was my betta being overly happy. I did a small water change, lowered the temperature to somewhere between 78-80 and sped up the filter. Plants are thriving, no more bubbles all is good. It seems to be water changes that make the bubbles go away.

    PS...I like the start date of 2012 :)
  9. Algae EaterWell Known MemberMember

    Whoops... lol I'll change that start date. Thanks for noticing!

    I'm definitely looking into other diffuser ideas other than a bubble stone and I've seen some DIY on the internet that look pretty easy. (Sorry, I don't have the links.) My CO2 reactor isn't working properly, so I'm going to tear it down and reseal everything. Needless to say, I haven't had any bubbles since it stopped working lol.

    I thought there was a test you could get to check CO2 in the water but I haven't found it anywhere! I also heard there is a math equation using ph and hardness to figure out the CO2 levels?? I haven't looked it up though.
  10. NutterFishlore VIPMember

    Here's a link to one of the KH/PH charts for you:  
    I don't find them to be the slightest bit accurate though so take the results with a rather large grain of salt.

    CO2 test kits can be hard to find. Many swear by drop checkers but I think they are the most useless invention in the world. Right up there with ejection seats in helicopters & flywire screens in submarines. There are liquid tests available but many are known to be inaccurate. The best one I have come across is from Vitakraft but I'm not sure if you can get it in the US. You have to be very carefull when using liquid co2 tests not to cause too much disturbance to the water while carrying out the test or the results will be skewed.

    For your leaky co2 rig, try making the holes in the lids by heating up a star screwdriver that is smaller than the airline. Get it really hot & then push it through the lids twisting it slowly as you go. Only heat the tip 1" of the screwdriver & when it goes through the lid, push the lid all the way up onto the cold part of the screwdriver shaft twisting it back & forth the whole time. Remove the lid from the screwdriver & you should have a perfect hole. Seal with hot glue on both sides of the lid if you still have doubts about the quality of the seal.
  11. Algae EaterWell Known MemberMember

    Thanks for the info. I cound only find one CO2 test kit by "Red Sea" but if there is no way to tell if it's accurate, I think I'll just skip the test, especially since it wasn't cheap! It was just a curiousity to find one, anyway.

    I was using a drill to make holes in the lids but it left little plastic curlicues around the edge of the holes that I can't get off. Then I used silicone sealant around the holes, just to be sure, but I had to wait 24 hours for it to cure. When I tear it down, I'll try hot glue, and if that doesn't work, I'll try your idea with the screwdriver once I get a hold of new lids.

    ejection seats in helicopters... lol
  12. RegalWell Known MemberMember

    I've used the drill and a hot nail to make holes in the caps. I think a hot nail (or screwdriver) is easier. I got the little plastic curlies too. A razor sliced them right off.

    Recently, I added another 2-liter to my diy set up. I had to take it apart and start over because there was a leak where the tube went into the cap. It seemed like the silicone just was not bonding to the type of tubing I had. It was from Pet Supplies Plus, made by Python and had a bluish tint to it. I went back and picked up a different type of tubing and it worked fine. It's a good idea to use a razor to get all the old silicone off if you decide to start over. Oh and another tip - when I redid this last one, I wondered if I put the cap on before the silicone had dried for 24 hours would the gas from the bottle make a big bubble in the silicone? Yes, it will lol. Make sure to let it dry.

    For the smaller bottle that is used to trap any goop coming from the bottles, it can be used as a bubble counter too. If you run the incoming tube to the bottom of the small bottle and put in a little bit of water at the bottom you can see the bubbles coming from the two liters. The tube that goes from the small bottle to the tank would still be short so it is far from the water at the bottom of the small bottle.

    I downloaded an aquarium calculator from Chuck's Planted tank web site that allows you to put in your KH and PH and it tells you your co2 ppm. (among other things)


    I have a question for you. I used the PH/KH method and it said I had 40 ppm in my 75 gallon with three 2-liter bottles of diy co2. I couldn't see how that could be accurate. I have crushed coral in my filter to raise the ph a little to counter the drop in ph from the co2. I have since read that if you are doing anything to alter your ph (like peat moss or coral) that the KH/PH calculator becomes useless. Have you found this to be true?

    Sorry Algae Eater, I didn't mean to hijack your thread. I was hoping this was kind of like a follow-up to your question so I hope that's ok. I just wanted Nutter's opinion because I thought I saw that he had a few tanks ... just a few :;laughing
  13. Algae EaterWell Known MemberMember

    I didn't think to use a razor blade to remove the curlies. I had trouble with the silicone, too, so I tried hot glue (earlier this evening) and it worked much better. Plus, it dries in a few minutes and if there is a problem it will peel right off just like the silicone. (I use it for everything around the house, I don't know why I didn't think to use it for this before Nutter even suggested it!)

    I do have water in the smaller bottle, but my thought was that it would help trap liquid and unwanted gunk, I wasn't really thinking about a bubble counter. So, what is the equation for how many bubbles equals the amount in my tank water?

    Don't worry about the hijacking. I was actually thinking about the same thing, and I think you are right, but Nutter seems to have answers for most of my questions, so I'm sure he has one for this one!
  14. NutterFishlore VIPMember

    This is rather confusing, so it might pay to do some extra research on top of what I've got to say about this. In other words, I could be wrong.

    The way I understand it is that so long as carbonate based buffers are being used, the KH/PH chart is supposed to hold true. From what I have learned problems with the chart start to arise when phosphate buffers are used. I don't believe lowering the PH & softening the water via the use of peat or RO water has any effect on the results from the chart. The important part is that your KH is the direct result of carbonates rather than any other substance. That could be wrong though as I gave up on researching that side of things when I realised that I really don't need to know the exact co2 levels in my tanks. I just worry about getting the co2 supply as consistent as possible & diffusing as much of the gas as I possibly can. I just make sure that plenty of co2 bubbles are getting diffused & that my water parameters, (PH & KH), are as stable as possible during both day & night. If I know I'm pumping plenty of co2 gas into the tank, I see the expected drop in the PH & the readings stay relativley stable both day & night, I don't worry about anything else.

    I also don't worry about bubbles produced per second. I just make sure that the supply is as consistent as possible. To that end I use 2 x 5lt bottles as generators with a little sump/bubble counter. The yeast mix I use lasts me about 4-6 weeks in the 5 lt bottles depending on the weather. If I were to make the yeast mix in one of the bottles today, I would make the next bottles yeast mix in 2 weeks. 2 weeks after that I would replace the yeast mix in the bottle I made up first, then 2 weeks later make a new mix for the bottle I made second. Alternating the new mixture like that gives much greater consistancy & helps avoid any unwanted algae issues. I also find that using the larger generator bottles made the yeast mix last much longer. I use 2 cups white sugar to 1/2 teaspoon of bakers yeast. In the 5 lt bottle it lasts 6-8 weeks before it stops producing bubbles depending on the weather. In a 2 lt bottle, the same yeast mix stops producing bubbles after just 1 1/2 to 2 weeks.

    All said, I apply the K.I.S.S (Keep It Simple Stupid) principle to my co2 injection. I know if I see my PH drop & my KH stay the same, that I'm increasing my co2 levels. I know that if I see my fishes gill rate rise, I am introducing too much co2.

    I hope that has helped in some small way though it is probably better for you to do some of your own research on the different KH buffers & thier effect on the PH/CO2 relationship.
  15. Algae EaterWell Known MemberMember

    Right now, I'd just like to get my CO2 working again. Last night, I tore it down and used hot glue instead of silicone and it hasn't created any pressure in the bottle whatsoever. I'm wondering if the problem isn't the fact that the reactor is beneath the tank and isn't able to get all the way up into the tank.

    I have done some research on KH, GH, and pH, buffers, etc. because I've been trying to lower the pH in my tank. I don't really want anymore test kits or things to do for the tank. I already do enough! I like your KISS principle, it sounds easier and cheaper, too! Thanks for the info! ~Chris
  16. NutterFishlore VIPMember

    The bottle being below the tank won't stop the co2 from reaching the tank. Either you still have a leak or you have a dodgy check valve. Probably a leack. If it was the check valve, the pressure would just build up until either the bottle or the airline exploded.

    Does the bottle you are using seal airtight around the lid? Are you using the soft, flexible silicone airline? The harder plastic airline is no good for getting a seal. Perhaps make a new lid up. I suspect the holes are too large for the diameter of the airline & that is why you are having trouble getting a good seal. The holes need to be smaller than the airline. Cut the end of the airline on an angle & it will be much easier to get it through the smaller hole. Make sure that there are no twisted bits in the airline as it pokes through the lid or that there are no bits of plastic poking from the lid into the airline creating a pin sized gap. The holes need to be PERFECTLY round. After inserting the airline, pull it back out a little way to help achieve a good seal on the inside of the lid. Seal the inside of the lid as well as the outside. Be carefull not to melt a hole through the airline as you apply the hot glue. You need to make sure there is plenty of hot glue around the airline & that it is in contact all the way around both the airline & the lid with no holes anywhere. Even a pin ***** sized hole will stop it working. Check that the leak isn't around the check valve. Use soapy water to find any leaks. Just make sure you don't use the soapy water on anything that will come in contact with the tank water. Make sure the mix is bubbling.

    You should be able to get an air tight seal without having to use a sealant of any kind so I'm surprised your having trouble. If you can't get it to work right, post a pic or two of the generator you have built & close ups of the seals & I will see if I can see something if you like.
  17. Algae EaterWell Known MemberMember

    Thanks for all the tips! I'll make new, tighter fitting lids, use a heated screwdriver or nail and a razor blade to get rid of the curliques, and use silicone tubing. The tubing I was using is soft and pliable, but I don't think it's silicone. If it doesn't work again, I'll take pictures! It'll be a while, though, because I don't drink much soda! ~Chris
  18. NutterFishlore VIPMember

    If the airline is the soft type then it probably is the silicone one. The plastic stuff is rather stiff & kinks very easily. You don't have to use a soda bottle either, you can use any plastic drink container that has a lid you can screw on really tight. I personally use 5lt bleach bottles that were cleaned out really well. If you want large containers for free, try your local hydroponics store & ask them if they have any empty nutrient bottles that you can have. Most will have heaps that they will be only too happy to give you.
  19. dragonsharkValued MemberMember

    hey Chris i have co2 one on my 55g and one on my 30g i used 2 2lt mt dew bottles( 1 for each ) took my bernzomatic and melted a hole in each cap used gel super glue to seal the check valve in the cap then ran a hose from it to my canister filter in my 55g and my over flow in my 30g not realy sure how much co2 im getting but i noticed a big dif. in the plants i use 2 cups of white sugar 1/2 Tbs of baking soda and 1/4 Tbs of dryed bread yeast i mix the sugar and the baking soda in the 2lt bottle with realy hot water about 1/3 full then i mix the yeast and a little sugar in a cup with warm water and mix that for about 2min then i fill the bottle up to 3/4 of the way with pee warm water then i pour in the yeat mix shake it up good then i bring back to my tank and hook it up and leave it alone it lasted me a little over a month my fist one i did lasted from 12-22-09 to 1-28-10 it was still going but i clean my filter once a month so i desided to change it at the same time hope this helps you
  20. RegalWell Known MemberMember

    Good luck with the new bottles. For the tubing just get the cheapest stuff they have. You don't want anything fancy, just the most basic tubing. I've drank half a 2-liter of Mountain Dew already today so I could help you out with that lol. Here's a link to a thread where I took some pictures of one of my diy co2 set ups for Tony.

    I don't even use the baking soda anymore. I put a funnel in the bottle, add sugar and yeast, add water, put an old cap with no hole on the bottle and then shake. That's it. Is there a reason why you do so many steps and different water temps? I use warm water to fill the bottle because if it's cold it won't activate the yeast and if it's hot it will kill the yeast. You are getting your mixture to last a month and mine only last 2-3 weeks so I'm interested in how you do things :)

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