Application for Calculating CO2

Interesting app for calculating CO2 level based on your KH and pH. Can also calculate how much fertiliser to add to your tank (although I don't understand how that bit works).

Link for download and installion is at the bottom of this page:

www.csd.net/~cgadd/aqua/art_plant_aquacalc.htm

Hiya Ken

Its a good calculator and accurate but probably a little dated now, we now use a drop checker method with a known fixed kh, usually kh 4, you add ph reagent into the drop checker and this will change colour depending on the amount of CO2 in the water, its much more accurate, the Ph/kh method of calculating CO2 (as in the above calculator) presumes that the only acid present in your tankwater is carbonic acid (carbon from the CO2) but this is where people had all sorts of problems measuring the CO2, because in most planted tanks there will be other acids present as well, you could have tannic acids from wood present, the substrate or gravel usually contains organic acids as well and all these things throw off the Ph/kh chart and give you false readings. So some people using the Ph/kh charts thought they were adding enough CO2 but in actual fact they were not and getting algae instead.

I will post up some pics later to show you what I mean and where you can get cheap drop checkers and 4dkh solution.

The other calculator on that site is for measuring the correct dosages if you use powder fertilisers such as potassium nitrate and potassium phosphate, but there is a whole list on the site of other chemicals fertilisers as well, basically its for people who make up their own fertiliser for planted tanks, I do this all the time saves a fortune instead of buying shop bought bottled fertiliser which is usually inadquate for highlight tanks, this dosage calculator is widely used with planted tanks and was the first of its kind that was computerised, its very accurate, I use it all the time.

Anyway hope that makes sense, will post back later with some links.

This is a CO2 drop checker



This is not my pic btw just taken from one of the ebay links below

CO2 drop checkers have been around for a few years and the common practice was to use water from the tank and then add some Ph reagent and this would change the colour of the solution in the drop checker and indicate the CO2 level in the tank, these days a better method is to use a fixed Kh solution that has been made up with distilled water and use this in the drop checker only, we do not use any tank water this will contaminate the solution and make the known Kh void. You then add some Ph drops, usually about 3 to the Kh solution and this changes to a blue colour, put the drop checker in the tank and a vacumn or airlock is created between the tankwater and the CO2 checker, in about 2 hours the drop checker solution will indicate how much CO2 is in the water, it will be green if you have 25-40ppm CO2 in the water( this is the colour you want for highlight tanks) it will be yellow-green if you are adding to much CO2 and blue if adding to little.

The reason the old method did not work is because it was only accurate if there were no ions acids or phosphates present in the water that would not affect Kh or Ph, it was based on the premise that only carbonic acid was present, now for a start we add phosphate into planted tanks so in a nutshell the charts became inaccurate, so by using distilled water and a known Kh we can accuratly measure CO2 levels(accuratly enough for our purposes).

Don't think im explaining it very well.......however

You can buy drop checkers from this guy if your interested, takes about 10 days to deliver, hes very reliable though, stuff comes from Malaysia, lots of other good things on this site as well, Ive bought lots from this guy with no problems, the glass CO2 diffusers are very good value, work well also, although avoid the nano ones, try his best offer auctions, these are best value, offer half of his buy it now price and he will normally accept, get good bargains that way, he usually responds quite quickly for those type of auctions, wouldn't buy plants though, take to long to arrive, although if you wanted moss this should be ok, I have done this before and it arrived ok. Look under CO2 equipment for the drop checkers.

stores.ebay.com/AquaticMagic_W0QQcolZ4QQ...ZQ2d33QQftidZ1QQtZkm

4dkh solution can be bought here

www.aquaessentials.co.uk/index.php?main_...05f8068a568f05d7693f

You can make your own Kh solution but it needs to be very accurate, you need a calibrated digital scales in order to make it, most people don't bother, a 250ml bought solution from the above link will last most people a couple of years at least changing the solution every 2-3 weeks or so.

Thatks Zig, that's very interesting.

I'm using a DIY CO2 system and have the CO2 diffusing through an airstone. It seems to be working reasonably well and I'm getting plenty of bubbles from the plants.

I'm sure there is a better way to diffuse that will maximise the my C02. My pH out of the tap is 7.8. I added a piece of bogwood which brought it down to 7.4. Adding the C02 brought it down to 6.8. I find when my CO2 starts to run low and the pH rises slightly to 7.0, the plant bubbling (pearling?) decreases and I start to get algae.

My current level of C02 may not be sufficient so I'll definitely try the method of measuring you describe above. I've also reduced surface distuption to prevent C02 loss.

I also see that the site you recommended also sells C02 diffusers. Any particular one you'd recommend for a DIY C02 kit for a 230l tank?

Hi John,
he's charging 6 US $ flatrate now.
@Zig,
they are also selling the drop checker for very little.
Holger

Ken its hard to know here, a 230L tank is quite big for CO2 diffusion using a glass diffuser although its probably better than using an airstone, you really need a pressurised system for a tank that size, normally I would recommend to use an external inline CO2 reactor but this would only work with a pressurised system, the other problem is that you are using DIY CO2 and it may not produce enough pressure for the ceramic disk on the diffuser to work properly, but I would say on balance it should be ok, I have seen these disks used with DIY CO2, the other problem with DIY CO2 is the residue it produces which may clog the disk, you use a diluted bleach solution to clean them, just leave them soaking overnight or for a couple of hours and then put them in some dechlorinator solution to nutralise the bleach, after that they should be ok to use again.

The best diffusers on the site are the Rhinox ones, these are used widely but mainly with pressurised CO2 systems. To give you an idea of how much CO2 you would need with a pressurised System for a tank your size to achieve the correct CO2 rate for a highlight tank, you would need to purchase the biggest Rhinox, that is the Rhinox 5000, and you would need to have about 2-3 bubbles per second to achieve 25-30ppm of CO2, and then you would need good circulation in the tank to blow the bubbles around, if they shoot straight to the surface the CO2 is wasted. I doubt if the Rhinox 5000 would work correctly with DIY CO2, this disk is quite big and the DIY may not produce enough pressure to make it work properly. So you can see the problems here, DIY CO2 will not produce 2-3 bubbles per second only a pressurised system will do that. TBH though most people would not use a diffuser of this type for a larger tank.

If you only have low light and reasonable circulation in the tank a ladder type diffuser would be a lot better than the airstone you have now and thats probably what I would recommend, he has them for sale on the site as well, I used a 2 ladders on a highlight 40 gallon tank for about a year with good results before I went pressurised, funny thing is I always enjoyed looking at the bubbles going up the ladder, lots of people say that.

@JohnH

John I noticed that as well although in fairness he does say it on the site, $6 for the first order and an extra $3 thereafter, I think the most I ordered from him at one time was probably about $15 postage worth and like you when the goods arrived the postage came to about 4 euro, but there again the goods are cheap IMO, but you don't have to go to ebay to get ripped on postage charges, the other day I was going to order 3 T5 lightubes from Aquatics online.co.uk (only small ones, 24W about 22 inches in length, easily fit in a smallish box) anyway checked out the postage and it came to £16.99 or €25 !!!! the company is in Cardiff not in Malaysia, needless to say I didnt buy them.

Holger the drop checkers are really good value, I got 2 for $20 include the postage it came to $29 or about €22 , €11 each, not bad IMO.

His prices aren't bad but did you check out his shrimps 399$ for 5 shrimp. Frigging hell and I thought lobster was expensive.

Do you know if he combines shipping? I might be interested in ordering some plants but don't want to fork out 6 $ shipping for each plant. I ordered plants online from Asia before and they made it over OK.

Actually hadn't noticed that, shrimp in asia are highly prized, the crystal red shrimp are thought to be the best, they are graded due to the markings on the body, the markings are not natural though, these are all bred to produce the colours and IMO whilst they look stunning they do not look natural in planted tanks. This is the most expensive I have ever seen CRS shrimp going for, I must bring this up on one of the planted forums, see what people think.

Yes he will combine shipping, $6 for the first order and $3 for each subsecquent one, so order 5 different items and you pay $18 shipping, if the items do not fit in the one box or envelope, he will post them seperatly, but at the same cost to you, also if you order don't expect an email back saying your order has been shipped, last time I ordered I got an email after the goods had arrived!! just expect them in about 10 days, he can be trusted though, he has a very good reputation on the more dedicated plant forums, some of the mosses are very good, weeping moss and christmas moss can look beautiful if tied onto branches and let grow, also the Fissidens are particularily good but maybe for more specilised use, they also grow incredably slow so may not be for everyone.

Thanks for the info.
You can bit on the same shrimp as well, starting at 99cents and the auction isn't running for much longer anymore. The shipping of 65$ is a bit hefty though
I was looking more at some of the ferns he is offering for my discus tank.
Any suggestion on this?

My favourite fern would be what he calls the narrow leaf fern on the site, the needle leaf fern grows shorter leaves but looks very similar.

Personally I dont like the Windolev fern it can also be a little difficult sometimes depending on you setup, its prone to browning of the leaves and they usually don't recover. I would pick any of them except that one maybe.

Not sure what way he sells the ferns, they may come as loose leaves that you may tie up yourself, he does say you are winning a bunch of leaves on some of the items, I do this all the time though and its not a problem, just use ordinary cotton thread and small bits of bogwood and tie them on.

Heres some ferns I tied up recently, the bigger one in the pic is probably 6 months old.



And a small one just freshly done on a small piece of bogwood



Although im sure the leaves will a lot bigger than the small one in my hand, that one is quite small, he says you will get x amount of leaves per order of whichever fern you choose, 20 leaves would be a very good amount IMO to tie one fern together, some of them he offers 40 leaves, you may be able to tie two ferns with that amount of leaves. Ferns are easy to propagate once they become established, just keep collecting the leaves until you have enough to tie another one up, I usually remove them from the tank and put them in some tankwater in a container until I have enough to tie another one, just make sure they get a little light and they will usually be ok for ages, stops them floating around the tank when they come loose.

Just another thing on the 4dkh solution, this is brand new on the aquaessentials site but there appears to be some confusion as to what pH reagent to use (from your testkit) im trying to clarify this atm with Richard the site owner, you may have to use a specific low range pH kit for the colours to change correctly in the solution, as you know some test kits are very bad when it comes to colour differences, some are so close you cannot tell the difference, so not all kits may be suitable, I will get back to this later and post the correct pH kits to use, if anybody is going to buy this you would need to know this as well.

Edit: just a quick edit, all of the ferns should do ok in a discus setup up to about 30C

Sorry Holger just changed some info about the different ferns from aquaticmagic im getting mixed up with a conversation from a different site, some had doubts about some of the names and what the actual ferns were , sorry about that if you read this earlier, everything he sells is what it says it is.

Glad to hear that there were some roots with it. makes life much easier.

(I hated plant propagation in college and don't think I will change my mind)