Questions regarding Drop Checker

[illumnae]

ok, but if that's the case, then why did the drop checker color changes to yellowish green (6.0 to 6.2) when I turn on lights and Co2? By the same logic, if the checker is not working properly due to ada soil causing the ph to stable at 6.4, the color should not change even if I turn on co2?

i did read your post carefully. you indicated that your drop checker colour changed to yellowish green did you not?

By the same logic, if the checker is not working properly due to ada soil causing the ph to stable at 6.4, the color should not change even if I turn on co2?

The colour will change when you turn on co2 even if you are using ada soil. my understanding of how a drop checker works is pretty layman, but i'll try to explain it here. perhaps someone with a better working knowledge can add on or correct me.

Basically, there is an air column in between the water level in your tank and the water inside the drop checker. CO2 diffuses out of the tank water, into the air column then into the water in the drop checker. The presumption here is that the level of CO2 that is in your tank water will be the level of CO2 that diffuses into the drop checker water via the air column, which is how you get a ph change in the drop checker water.

Now, if your tank water is inside the drop checker, given that the CO2 will affect the tank water as much as it affects the drop checker water, it comes as no surprise that the ph readings on the drop checker and via your ph pen in the tank are the same. By using tank water, you are making the drop checker redundant. you may as well just measure the ph in your tank (as you are doing now) and do away with the drop checker totally.

as for using distilled water with a known kh value. the purpose here is to eliminate as far as possible all other variables in the equation. the ph/kh chart, as explained by PeterGwee, is only accurate when the kh is caused only by bicarbonate and the ph is affected only by co2. any other additives in the water will affect the reading in some way or another. What the drop checker really does is to make sure that the actual amount of co2 in the tank water diffuses into the drop checker, which contains a controlled solution that accurately reflects the ph/kh table so that you are able to obtain a more precise (well as precise as ph solutions can get anyway) reading of the co2 level in your tank without any other variables getting in the way and affecting the readings.

this is useful if you require a more precise knowledge of the amount of co2 in your tank (since 30ppm is the recommended amount). if all you're looking at is the number of shrimp hanging at the surface, and you're satisfied with "less shrimp are hanging at the surface" being an indication of optimum co2 in your tank, then by all means dump/sell/store your drop checker because you won't need it.

[o2bubble]

Thanks for your long explanation. But like I said I will stop arguing on this and waiting for ADA to reply my email on the drop checker questions.

But, I just want to correct you that I DID NOT mention the amount of CO2 is right/suitable for yellowish green color as you stated in your post. I'm only stating the obervation that the yellowish green color is consistent with my ph reading results when the Co is turned on. Maybe you misunderstood my post. This what you wrote: "when you inject the CO2, the ph drops further and shows yellowish green, indicating that you have too much co2 when in fact you have just the right amount."

Lastly, I respect yours and other senior bros views on the drop checker usage but I cannot agree at this moment unless I clear the doubts I have and I trust that my PH pen is accurate. (Just calibrated 1 week ago)

I will also go get a CO2 test kit later to confirm the exact amount of CO2 in my tank.

i did read your post carefully. you indicated that your drop checker colour changed to yellowish green did you not?

this is useful if you require a more precise knowledge of the amount of co2 in your tank (since 30ppm is the recommended amount). if all you're looking at is the number of shrimp hanging at the surface, and you're satisfied with "less shrimp are hanging at the surface" being an indication of optimum co2 in your tank, then by all means dump/sell/store your drop checker because you won't need it.

[illumnae]

as i've mentioned, i trust that your ph pen is accurate too especially since this affirms what i said about your tank water and drop checker being supposed to register the same ph because of your use of tank water

but yeah no point arguing if you don't agree. it isn't an easy concept to grasp and to be honest, your questions did get me thinking and it took me awhile to turn the thoughts around in my head before i dared to post.

[o2bubble]

Bro illumnae, I agree conceptually on the working of CO2 drop checker. Please do not get me wrong. What I do not agree is on the grounds that tank water with ADA soil cannot be used because based on the belief that it will lower KH to 0 and ph to near 6.0. So far, my KH has been consistent for 2 months now at 3 with no additions of carbonate powder to increase KH or other chemicals that might affect KH. I'm not sure why also since my tap water is KH 2 only.

Well, the best options to clear my doubts immediately is to use a CO2 test kit to determine the exact amount of CO2 before and after CO2 is turned on

[illumnae]

possibly the ferts that you add. magnesium and calcium in the ferts would probably raise your kh.

i may be wrong, but i've read before that CO2 test kits are notoriously inaccurate, so do take your results with a pinch of salt. there's another method somewhere on an old post in the forum giving an alternative method of testing CO2 (i think it involves standing your tank water for 24-48 hours and then measuring the ph difference in the water and the tank water) which you might want to use instead

[o2bubble]

oh, I see... that may explan why my KH level remains constant at 3-4 even when the new water from my tap is only 2.

I will try the test kit first. I think they should give a fair even if not 100% accurate readings.

I can't find a co2 test kit at LFS. All are sold as CO2 indicator/checker. Sigh, however after reading the article posted earlier, I guess it does make sense to use a reference solution of KH 4 to avoid interfaces of KH/PH in tank water. I will do this later at night and use with my ADA drop checker.

The article also alerted me a valid point that insufficient co2 may cause BBA to appear and indeed that after lowering my CO2, I'm starting to get tiny patches of BBA on my driftwood now. Maybe, it might be true that my CO2 is not enough.

I will find the distilled water to mix with Na2CO4 powder or KH 4 reference solution later to try. Still waiting a reply from ADA as well.

Btw, does any bro knows where to find KH4 reference solution? C328?

[illumnae]

not sold in singapore i think, Peter did mention to order it from overseas suppliers. what i did to make my kh4 solution was buy a bottle of watsons distilled water, add in a VERY small pinch of baking soda to half the bottle, then slowly add in water and keep testing till it's kh4...quite a tedious process

[o2bubble]

I did recall seeing a KH 4 or 5 solution in some LFS. But the problem is I can't remember which one!?? Getting old now or did I imagine?? Anyway, I called a few and they all said "no".

Found an article on how to create a simple KH4 solution with fair accuracy: http://www.fishforums.net/content/Pl...wtopic-169942/

Can't find the KH reference solution at Hach site. I ordered one bottle from bill in US instead: http://liquidarthome.net/khstandard The cost including shipping should be about $15, still checking with him.

[illumnae]

you should try and see if you can organise a mass order to save on shipping costs, i'm sure you can get a number of people on the forum who want to buy the solution as well. it'll take slightly longer as you need to be certified by the mods, but it cuts some costs and helps out others on the forum

[Burnz]

I must say that this thread has some rather spontaneous and informative discussions /links that is really beneficial to aqua-tech noobs like myself. Thank all who dropped pointers and opinions to trash things out

[Shadow]

Isn't that interesting? It make you think instead of just blindly take suggestion.

[o2bubble]

I want to help and do a mass order for KH solution but its really too tedious. Have to submit photocopy of IC to AQ, wait for verification and approval and have to posted strict details etc... Below is a reply from Bill (in USD), not cheap, total cost I think about SGD35... Those who are interested can pm me personally to buy together by this weekend and I will pay for it first (Not a mass order over forum):

"The KH Standard is $6.99 for a 500ml bottle.
The cheapest shipping I can find to Singapore is $15.90 via USPS, this is the actual cost I didn't add anything to the shipping price. The time is usually about 2 weeks when shipping First Class to Singapore.

You can pay thru PayPal.
Let me know when you want to order a bottle and I can send you a request for money via PayPal, this will makes thinks a little easier.

If you have anymore questions, feel free to ask.

Bill"

[illumnae]

how many bottles can you ship under the $15.90?

[Burnz]

Isn't that interesting? It make you think instead of just blindly take suggestion.

Yeah Robert, thats why they say 2 brains ( or more ) is better than 1.

Last question. What if i am using non -ADA substrate but just normal lapis with regular liquid fert dose. Would that make the drop checker redundant? Or would it still be advisable to go with kH 4 solution, distilled water or even tank water in this condition as previously discussed?

Still need to sleep on this issue

[Shadow]

It is not redundant. To be save use kH 4. You can make your self using distilled water and baking soda. Anyway it is all about estimate no need point accuracy. or you can asked O2bubble to buy for you. 500ml is a lots, can last very long.

[o2bubble]

Ordering will takes about 2 weeks. This weekend, I'm going to try make some using distilled water and sodium bicarbonate powder to see if my drop checker really inaccurate due to tank water. I have also up-ed my CO2 level back to 3 bps last night. Will observe if any improvements to my tank tonight.

[rc311]

Hi,

Indeed good information to share... By the way, is the JBL Permanent Test CO2 plus PH is also consider a drop checker?

Cheers
RC311

[o2bubble]

JBL test co2 is also a drop checker type. The only one I can find in Singapore which is purely test solution based is AZ00 and tetratest master test kits package (ph, kh, gh, nitrate, ammonia, co2 etc). However tetratest does not have individual co2 test kit, very strange. Azoo one I have no confidence on it.

Did a check last night after increasing my co2 to 3 bps previous night and seems like no much change in color. Maybe it's because I did added some fertilisers with additional N and P and increased the uptake in CO2. However, I did observed more shrimps staying near water surface, co2 drop checker is more green during lights off (still yellowish green during lights on) and more bubbling. Seems like my N and P were the limiting factor.. Hope I have time to get the KH4 solution up this weekend to use with my drop checker to confirm my CO2 level is enough.


By the way, is it possible that more shrimps staying at the water surfaces even when lights are on due to change in PH with more CO2 level?

[o2bubble]

Hi all, i managed to make 350ml of kh 4-4.125 after messing around with distilled water and soda powder for 1.5 hrs my drop checker show dark blue with it. Will check the results tomorrow. Also, will not order the kh4 standard solution now.

Initial results, before change water and co2 on, ph was 7. After change water and co2 on, ph 6.8 (19 ppm co2). However, the result may be affected by the water change and will wait one more day to determine the final result to confirm.

Checked last night. On co2, 6.6, off co2 7.0. Thus my co2 is at 30ppm when on and sufficient. However when using my tank water it was indicating 6.2 which is wrong. Thanks for all the pointers! Lastly no update from ada yet.

[ct13]

Thank you all for your input for the drop checker, too tempting and finally got one for myself today.

Mixed the distilled water with Sodium Bicarbonate till 4kH, fill up half ball & drop 4 drop of the regent. The water turn blue, monitor it for one hour and the colour change to greenish blue. Decide to increase the bubble count from 2bps to 3bps.

Just came back a while ago and the colour now is green, my pH is 6.55. Find it fun & very useful.


Thanks all.