# question w/ kH, pH, CO2 and aquasoil relations



## mphering (Oct 3, 2005)

I have a tank set up and running to keep a few fish alive untill I am ready to do a full plant tank setup. I am about ready to start the whole plant setup and have been testing my water so I have an idea of what sorta water perameters I will have or strive for. So with my current setup (not adding CO2 and no plants) the water has a KH of >1 and a pH of 6.1 - 6.2. but my tap water is kH of 5.0 - 5.5 and pH of 7.0 - 7.2. Does aquasoil really lower the kH and pH that much? I do also have a lot of wood in the tank. I don't know if it matters but I am only running 1 wpg for 12 hours for the fish untill I put plants in. Another question is I under stand how the kH pH CO2 chart works but I am a little confused. I have read that the only way to get co2 into your tank is to inject it witch I plan on dooing but, does that mean with my tank now at kh 1 and pH 6.2 according to the chart there is 19ppm CO2, but I am not adding any CO2 yet. So does that mean once I do start adding C02 the pH will not start to drop untill the water reaches 19 ppm of CO2? or will it start to drop right away? pase help I have to know for sure before I jump in. Thanks!


----------



## chiahead (Dec 18, 2004)

Aquasoil will lower KH/GH and PH due to drop in KH. I am not sure how or why it does that but it does. At least for a little while. If at all possible I would try to avoid fish for about 1 month. Some get away with shorter. Its up to you but besides the ph issues, aquasoil does have a fair amount of ammonia in it, which is great for plants, bad for fish. Maybe if you pack the tank with nothing but nutrient hog plants and do biweekly water changes it may be ok. If you have fish you want to keep I would try a quaranteen tank for a while just to be sure. As far as the kh/ph Co2 scale. I think due to the kh dropping you cannot truely go off that chart. It would be similar if you used a ph up or down product or acid buffer. It throws the chart off. I dont know all the technical reasons behind this, just what I have observed myself and also been told. Good luck!


----------



## mphering (Oct 3, 2005)

chiahead said:


> As far as the kh/ph Co2 scale. I think due to the kh dropping you cannot truely go off that chart. It would be similar if you used a ph up or down product or acid buffer. It throws the chart off.


So do you think I should go by my tap at kH 5.5 and use the chart or should I just go for a 1.00 pH drop like I have been hearing about. Do you think I should add baking soda to get a higher kH?

I appreciate help and opinions from all..


----------



## chiahead (Dec 18, 2004)

I do not measure my Co2. All I do is adjust it slowly over the course of a few days until the fish gasp a little then back it off a little bit. To be honest I do not know what my measurements are unless I start having problems. then I measure them. The AS will not suck the KH forever. It will fade away when the soil balances. Probably over a few months I have noticed. I am working through this same issue currently and have also gone through it before on different tanks. I was adding buffer every day that equalled about 5 dkh and every day it would drop to 0. Not too sure but I was having issues with growth and fish health during this period. I should of just done as recomended and just pumped up the co2 excessively and no fish for at least 1 month. Co2 is very cheap, fish are not.


----------



## mphering (Oct 3, 2005)

chiahead
my tank is 110 gal. and I only have 3 small fish in it aquasoil and wood and the fish are fine but since I started measuring the pH it has dropped constantly. from pH of 7.0 -7.2 down to 5.58 this morning (fish still fine) So the what do you think of just leaving it the way it is and waiting to start the plant think when the aquasoil stabilizes? and could I add little amounts of baking soda to speed up the processes?


----------



## chiahead (Dec 18, 2004)

I dont know if adding baking soda would speed anything up. It just has to take its course. If you want to avoid the big ph swings when the Co2 kicks on then trying to keep the kh up is advisable in my opinion. Even if that means daily adds of baking soda. This is just my opinions and others will surely say I am wrong. It just makes me feel better if the kh is there to prevent huge ph swings.


----------



## mphering (Oct 3, 2005)

chiahead
I am not adding CO2 yet. I will be once I add plants. I just want my aquasoil to stabilize before I start that. Or is there no reason to wait? I just want to know what to expect once it is all set up (with plants and co2 and aquasoil stabilized) as far as kH and pH with a tap water at 5.5 kH and a 7.2 pH? Maybe I am going about it all wrong and just need to do it and find out I don't know.


----------



## chiahead (Dec 18, 2004)

I would recomend to you to remove your fish, pump the co2 in high for at least 2 weeks. Then slowly add some fish. Until the fish are in there, do not worry about ph/kh.


----------



## mphering (Oct 3, 2005)

why do I want to add co2 if there are no plants? I don't understand..


----------



## dennis (Mar 1, 2004)

Add your plants also Plant as heavily as you can afford, crank up the CO2 and do 30-40% water changes every 5-6 days. Don't worry about your kH, pH or anything else. Well, you can check you Gh levels on the first day but don't worry unless it is below 3-4 degrees. Run your CO2 24/7 at about 1 bubble per second for every 20 gallons. This is a startign point and you can add more or less once you see how the plants react. Start running your lights at least 2wpg for 8 or more hours a day, 10 woudl be best.

After the 3rd water change start changing the water every week. You may want to start adding some nutrients at this time also. If you are using straight AquaSoil w/o Powersand then you should add 1/2 doses of nutrients from day one. Some people have a different opinion on when to start dosing but I feel much of that is decided by the density of your planting and the healthy, growth state of the plants. Shortly after the first water change you should add some fish, shrimp and snails as a clean-up crew. SAE's, otos, japonica shrimp, Nerite snails, etc. Now, before you do this take a water sample (a glass full, cup, etc) and aerate it over night then check the pH. Now, check the pH of your tank right before the lights come on. You are aiming for a 1.0pH drop. Don't worry about the kH. If your in that range you can add your cleanup crew. If not adjust the CO2 rate and then add your clean up crew. Now start dosing full stength nutrients. Watch yoru fish/shrimp and the plants and add more or less CO2 as necessary. After the 3rd or 4th water change you can start adding your fish.

Now, plant your aquarium and take photos to share with us


----------



## mphering (Oct 3, 2005)

dennis
Thanks for the hlep! one other question about the co2 chart. if I have kH 1 and pH of 6.0 before co2 injection does that mean that once I start adding co2 the pH will NOT go down untill the co2 is around 30ppm.....OR does that mean the pH will start to drop as soon as there is more that 2-3ppm co2?


----------



## dennis (Mar 1, 2004)

It will start to drop immediatly. For example, I turn off my CO2 at night. Some of the dissolved CO2 off gases overnight but I have low surface movement and a tight fitting hood so not all of it escapes My CO2 comes on with the lights at which point the pH is around 6.5-6.6 Over the course of about 1-1.5 hour the pH drops to 6.1 where it is shut off by my controller. 

Here is an example of using the 1.0 unit pH drop as a starting point. My settled and aerated aquarium water has a pH of 7.4 so I started this tank with my controller set to turn off the CO2 at 6.4 (if I did not have a controller I would simple use a slightly lower bubble rate so that the pH dropped to 6.4 but never really went below that). I observed the plants growth (or slight lack there of) and my fishes health as I slowly lowered the pH controller to shut off at .1 steps lower over the next few days. At 6.1 the plants responed the best and the fish were not showing signs of stress. At 6.0 the fish showed signs of stress so back up I went to 6.1 where everyone is happy.

I occasionally check my kH now whenever something does not seem right. I am not using Aquasoil and my kH occasionally shifts with seasons and weather. I do not use the kH/pH chart, but if my kH goes up or down it can affect me ONLY because I use a controller. If I was relying on bubble rate alone I would not have to worry about kH becasue you are injecting the same amount of CO2 regardless of kH or pH but a controller uses pH as an indication of where to shut of the gas. Does that make sense? 

Becasue I use a controller if my kH goes up, I inject to much CO2 and stress the fish; if my kH drops the I will be injecting less CO2 as the pH shift will start at a different point.

Does that make sense?


----------



## mphering (Oct 3, 2005)

dennis thanks for the help! one other question. if before I start injecting co2 the kH is 1 and the pH is 6.0. does that mean that once I start injecting co2 the pH will not start to drop until it hits 30ppm co2? OR will it start to drop as soon as I start to injecting co2 and and the ppm raises above 2-3.. that part is a little confusing.


----------



## mphering (Oct 3, 2005)

sorry, forget that last post (4:54 pm)


----------



## mphering (Oct 3, 2005)

dennis.
yes that does make since. I too will be using a ph-co2 controller. my ph in my tank (settled and aerated) is at about 5.2 ph, it seems like once I start adding co2 and get the ph down to the 4.2 range I will be too low?


----------



## dennis (Mar 1, 2004)

Where the heck do you live!?!?!? Now I am thrown for a loop and I see why you were worrying so much. Maybe ther eis some cunfusion on my par though...could you do me a favor? Post everything you know about your water, where you live and your tank setup.

you said..."pH in m y tank settled and aerated is 5.2" IS that using the controller? What type of controller? Are you positive it is calibrated correctly? Are your lights on while you check this? This is water, from the tank, in a glass, that you have run an airstone in overnight?

Just for fun, what is your tap water parameters? kH, GH adn what type of kits are you using?


----------



## chiahead (Dec 18, 2004)

Dennis he is saying that his PH in his tank just sitting with no Co2 added is 5.2. His tap PH was 7.2 or so from the first post. See the issue here is that the AS sucked all of his KH so in turn the PH dropped to 5.2 with no Co2 added. From what I can tell from researching this today is that you need to do at least weekly or biweekly water changes for the first month. Also, I found out that Brighty K is strongly recomended during the first few weeks because it has a KH buffer in it along with the K and dechlor.

Just curious how long has the tank had the water and powersand in it?


----------



## chiahead (Dec 18, 2004)

mphering said:


> dennis thanks for the help! one other question. if before I start injecting co2 the kH is 1 and the pH is 6.0. does that mean that once I start injecting co2 the pH will not start to drop until it hits 30ppm co2? OR will it start to drop as soon as I start to injecting co2 and and the ppm raises above 2-3.. that part is a little confusing.


Your Ph will drop as soon as you start to add Co2


----------



## mphering (Oct 3, 2005)

chiahead, yes that is exactly what I am saying. thank you. 
the tank right now only has aquasoil. It will have first layer flourite and them the aquasoil over. but I am not quite ready to buy the plants and plant (time issues) I will be able to do so in about a month. other than that I am 100% ready to go. all i will need to do is move the 3 fish. drain water and remove aquasoil. add flourite, aquasoil, plant the tank and fill up. I have spent the last year and half buying everthing I will need, and building the stand and canopy. it is a 110gal. tank. the 2 canister filters have been runing on a friends tank for the last 4 months so they are ready and working great. So anyway, an older little tank i had cracked so I figured set up my new 110gal. put aquasoil and wood in it and I have a home for my 3 fish. so everything is set up and running EXCEPT FOR CO2, only 1 wpg (it will have 2.85 wpg when plants are added) I figued this would be a good opertunity to see what kind of water conditions i will have or should expect. so far it has been 10 days and i have done one 1/2 tank water change. but I haven't started testing untill 3 days ago. the ph is tested by my pinpoit CO2 controller and all the other test are done by a hagen test kit. the pH controller was right on when I went to calibrate it. i didn't have to do a thing. I live in california on the central coast. we get state water.


----------

