Best Practices: Kh, Ph And Raising Them

[waterdrop]

Have you ever had a problem you're trying to learn about and there are just too many areas to learn all at once? While trying to understand why my fishless cycle was so slow I discovered that I probably have very soft water, despite my thinking I had hard water. My KH is zero or one (I think), which sets me up for extremely quick pH drops from my tap (pH=7.6 highest) down to pH 6.0 (bottom of my API pH test) when my nitrifying bacteria process my added ammonia over to nitrates. This sets me up for irritatingly frequent water changes attempting to get the pH back up where the bacteria like it the best (7.5-8.6) using my tap water that is only 7.6, but which overnight drops to 6.0. So it gives me problems now during fishless cycling and I anticipate there will be some problems associated with the normal running and maintenance of my future funtioning aquarium. Whew!, End of intro, and please be gentle on me, I'm a newcomer as you know and certainly not very experienced in water chemistry.

So, IF (a big if) I were to do something about this I would need some background knowledge and one piece of that puzzle for me is to learn What is Best Practice for Raising KH (and probably pH) on a steady basis?

Now, in my homework, I've gathered several possible practical actions:
1) add some crushed limestone in one of the filter baskets (limestone will raise general hardness (GH), carbonate hardness (KH) and pH)
2) add some crushed coral in one of the filter baskets (I don't know how it compares to limestone)
3) add (somehow) calcium carbonate (CaCO3) to the tank (but isn't this just limestone anyway?)
4) add baking soda to raise the KH (supposedly the first bit raises KH but resists raising pH?)
5) add limestone rocks or coral substrates (low on my lists, don't care for these, but being complete here)
6) add commercial alkaline buffer products

I suspect items one and two above are preferred by aquarists from various threads I've read.

What I think I'm after at this point is whether experienced aquarists find any of these much preferred (assuming they have to be done at all) and what the various long-term ramifications, problems etc. might be. I'm aware of the general precautions against bothering to artificially go with a different pH than your tap water, so I'm not trying to get admonished for that. I'm just trying to build up some understanding of practices so I can better approach my real questions. For my tank -after- fishless cycling I'm thinking that pH=7.6 is just fine (community tank) but that KH needs to be raised or I will be needing nearly daily water changes!

OK, bye, must go to theatre tonight so please excuse absence of response or thank-yous but I'll chk back when I can! Your friend, ~~waterdrop~~

 

[monkey_biz]

ok ive gone through this today in another topic but here goes.......
ps im a swimming pool plant engineer so i do this day in day out

1) add some crushed limestone in one of the filter baskets (limestone will raise general hardness (GH), carbonate hardness (KH) and pH) yes yes and sort of
2) add some crushed coral in one of the filter baskets (I don't know how it compares to limestone) the calcium will leak out but will continue to leak as long as its in there
3) add (somehow) calcium carbonate (CaCO3) to the tank (but isn't this just limestone anyway?) tuffa rock but increases TDS (total dissolved solids)
4) add baking soda to raise the KH (supposedly the first bit raises KH but resists raising pH?) bicarb will raise the total alkalinity and TDS and increase ph to about 8 but will settle again
5) add limestone rocks or coral substrates (low on my lists, don't care for these, but being complete here) to many other imputities in limestone and for coral see number 26) add commercial alkaline buffer products all bicarb based or bisulphate basedincreases tds you are adding chemicals on top of chemicals on top of chemicals and you will never balance your water
so............
mug your wife when she is sleeping and steal her tights/stockings.... fishnets will not do
drop oin a palm full of crushed coral in there and drop that in your filter and check after a week or so add or remove to get the correct balance. simple to do and a natural way of doing it without chemicals

 

[waterdrop]

ok ive gone through this today in another topic but here goes.......
ps im a swimming pool plant engineer so i do this day in day out

1) add some crushed limestone in one of the filter baskets (limestone will raise general hardness (GH), carbonate hardness (KH) and pH) yes yes and sort of
2) add some crushed coral in one of the filter baskets (I don't know how it compares to limestone) the calcium will leak out but will continue to leak as long as its in there
3) add (somehow) calcium carbonate (CaCO3) to the tank (but isn't this just limestone anyway?) tuffa rock but increases TDS (total dissolved solids)
4) add baking soda to raise the KH (supposedly the first bit raises KH but resists raising pH?) bicarb will raise the total alkalinity and TDS and increase ph to about 8 but will settle again
5) add limestone rocks or coral substrates (low on my lists, don't care for these, but being complete here) to many other imputities in limestone and for coral see number 26) add commercial alkaline buffer products all bicarb based or bisulphate basedincreases tds you are adding chemicals on top of chemicals on top of chemicals and you will never balance your water
so............
mug your wife when she is sleeping and steal her tights/stockings.... fishnets will not do
drop oin a palm full of crushed coral in there and drop that in your filter and check after a week or so add or remove to get the correct balance. simple to do and a natural way of doing it without chemicals

ha,ha, thank you for answering, believe it or not I already wrote your id in my notes from your other post because we have a family of swimmers, not to mention the fish tank. Plus also thanks because the regulars probably won't cruise the scientific section for an eon...

OK, I'm too inexperienced and don't understand your answer. On the corel you said:
"the calcium will leak out but will continue to leak as long as its in there"
Are you saying the corel will raise the KH but will leave a bit of something less than ideal?

I think I hear you saying that you prefer corel over limestone, right?

I think my ideal would be to raise KH (which I assume almost always raises GH too) but not raise pH very much at all. We haven't finalized our stocking list for fish or plants yet so I haven't got that important factor to take into account yet. It may even be that we'll choose some fish that like it more acid and will be glad of the lower pH but I'm sure I'll never be very happy that the water is so unbuffered that the pH could make quick changes. I need not only to understand more about gh & ph but also to find experienced aquarists who can tell me if I'm being overly concerned.

~~waterdrop~~

 

[TwoTankAmin]

I can only answer from experience re adding a bad of crushed coral to a filter. The key here is that the amount of cc inviolved is relatively small compared to the water volume, i.e. way less than using it as one's substrate or a part of the substrate.

My need was to raise kh while haveing a minimal or no effect on other parameters. I was concerned about kh levels and use of pressurized co2. My goal was to get and hold my kh at 4 or so. The tank is 50 US gals., heavily planted, with 144w of power compact lighting. My tap water params are pH 7.4, gh 6 and hk 5. However, my experience was that my kh levels tended to drop over time towards about 2.

I added approximately 1 cup of crushed coral in a bag to the Eheim Pro II canister that runs on the tank. The effects of the coral occur as it begins to dissolve slowly into the water. In this small an amount it took a while (weeks) for the effects to impact the tank. I noticed no change in pH but did measure an increase in kh. I did not test for gh, but I would assume there was some slight increse. I also assume that had I used a larger amount of cc that I would have gotten a measurable level of pH increase. I also assume that if there was a slight increase in pH caused by the cc that this was counteracticed by the pH decresing property of the added co2.

After doing more in depth research into the use of pressurized co2 and kh, I concluded that the odds of a co2 induced pH crash in the tank were so small without the addition of the cc that I removed it after about 6 months.

The following comes from the mirror site for thekrib.com, FINS

Hardening Your Water (Raising GH and/or KH)

The following measurements are approximate; use a test kit to verify you've achieved the intended results. Note that if your water is extremely soft to begin with (1 degree KH or less), you may get a drastic change in pH as the buffer is added.

To raise both GH and KH simultaneously, add calcium carbonate (CaCO3). 1/2 teaspoon per 100 liters of water will increase both the KH and GH by about 1-2 dH. Alternatively, add some sea shells, coral, limestone, marble chips, etc. to your filter.

To raise the KH without raising the GH, add sodium bicarbonate (NaHCO3), commonly known as baking soda. 1/2 teaspoon per 100 Liters raises the KH by about 1 dH. Sodium bicarbonate drives the pH towards an equilibrium value of 8.2.

 

[waterdrop]

Thank you very much. That's very interesting. If my information is correct that the two nitrifying bacterial populations prefer a pH of about 7.5 to 8.6 then in the context of fishless cycling it would seem that baking soda might not be a bad addition for somebody like me with KH (carbonate or temporary hardness) of zero to one degree to slow down the water changes. I'm thinking of the water at this point as just a bacterial growth medium, so it might as well be optimized. Later its discarded before fish anyway.

For longer term once there are plants and fish it will be a little harder to decide whether minor use of crushed coral would be helpful or not.

I've seen one statement elsewhere that implied that crushed coral produces its effect a little faster than limestone. Anybody agree with that?

~~waterdrop~~

 

[monkey_biz]

the key is the amount of crushed coral. what you are trying to achieve is balanced water for your tank, keywork balanced

literaly a small palmful will buffer your ph slightly increase your gh and kh and give youwhat you need. as long as you do water changes on a regular basis trial and error will tell you the right amount of coral.

backing soda or bicarb will raise the ph and buffer your carbonate hardness but will increase the amount of total alkalinity of the water so unless the fish you chooserequire a vey alkali water dont add it.
your TA will be about 40-60 from your tap water adding even a spoonful every now again will increase it to over 150 is such a small volume of water. unless you can test for TA dont mess with it. in a pool with 150 cubic meters of water 2.5kg of bicarb will increase the TA by 60-100....... can you see the importance now.
go the easy route and slowly raise it with coral as limestone/tuffa ect increases TDS. to high a tds and it would be like trying to breath in a smoke filled room.

have fun and enjoy



ps my tank is a small jewul 96 with a small canister and a palm full of coral. my readings today are remembering ive soft scottish water....

ph 7.4
kh 8-10 deg
gh 8-10 deg

 

[waterdrop]

Once again, thank you monkey and twotank. I've even taken the suggestions to heart and decided to experiment on my own tank. I've finally dumped 1.5 teaspoons of baking soda in to my 28G that is fishless cycling. I did it this morning after a 99 percent water change to once again raise the pH back up from 6 to 7.6 and at the same time as I recharged to 4ppm ammonia. The KH part worked like a charm, I measured 4 or 5 german degrees hardness with my KH test after adding the baking soda. I'm now hopeful the pH won't drop quite as fast - we shall see. I also picked up a bag of florida crushed corel which I may decide to use later in a very small amount in my external filter, although I'm very undecided about its use at all after my bio-filter is finished and I have fish.

So that's all great and I'm learning, but let me say for the sake of other folks that I didn't quite intend this - it would be more appropriate for me to do my learning over in New the the Hobby or Tropical Discussion I suppose. I stuck it here in the Scientific forum hoping to stir up a thread that would be useful to all of us later if we captured "best practices" in GH, KH and their pH relation. There is a nice old web page here:

http/www.drhelm.com/aquarium/chemistry.html

which Bloo and other members have referenced in various TFF threads and which I found helpful earlier when doing my homework. But I was thinking it would be nice to hear from a bunch of TFF members re -why- they like crushed corel better than limestone, or -why- they do or don't use baking soda. Or, here's another question: How long should I expect my baking soda to have an effect? (In my case it will probably be gone with a water change soon as I don't really expect it to hold off my pH drop for all that long.) Anyway, anyone?

~~waterdrop~~

 

[monkey_biz]

hi there
as baking soda is an alkali and a saturate, the saturate levels will drop with water changes or will maintain (well up and down) with another source is the coral but the ph will drop as acid is introduced ie co2.
as your tank matures and your nitrate level increases the ph will balance out naturally and give you your true ph level with fish. remember EVERYTHING you put in your tank will leak out something, id be more concerned of a very low pg and kh after my tank had matured and was stocked BUT a lot of fish like it that way. what do you intend keeping???
if its a community tank you will have to take a mid point and adjust to that.

at the end of the day its your tank, your water and your fish what works for me or any others might not work for you in the long run.
if you are concerned get your tap water checked as it may be saturated in acidic metals or high in phosphates ect.......

alkali
ammonia
nitrite
nitrate
baking soda
crushed coral
tuffa rock ect

acid
co2
phosphate
bogwood
peat

water chemistry is facinating, i deal with it every day and love it. just dont jump in and add to much. sometimes the easy options are the best. have fun and keep us updated

 

[waterdrop]

"baking soda is a saturate"
Let me see if I've got this terminology right as I'm not quite sure. Is baking soda just being called "a saturate" because it is a substance, which, in water, will reach "a saturation point", dependent on temperature, at which the medium (water) will be saturated, thus unable to hold any more of the substance, and the baking soda will be ready to precipitate out. (Presumably, if the temperature drops and the conditions are right, the water may become "super-saturated" with baking soda prior to (calcium bicarbonate?) crystals forming, right?) (remembering from chem, years ago..)

So if this is right, it goes right along with baking soda being a creator of -carbonate hardness- (aka temporary hardness) because the definition of temporary hardness is that hardness that can be removed from water by raising the temperature (as opposed to the hardness that can't, called permanent hardness (aka general hardness)) (this all sound right?)

Here's a different question: Should one be concerned of any lasting effect of using the baking soda during fishless cycling? My assumption is that the small amount dissolved into the water stays dissolved and is then lost when doing the 90% water change at the end of the process. I would think there is no chance the calcium bicarb would precip out on any surfaces and remain, or if it did it would be an insignificant amount. Does that assumption sound correct?

 

[monkey_biz]

ok.....
bicarb (NaHCO3) is a mild alkali, it will increase the amount of alkali in the water without raising the ph to much, closer to its native 8 but normaly about 7.7.
NaHCO3 is mainly prepared by the Solvay process, which is the reaction of calcium carbonate, sodium chloride, ammonia, and carbon dioxide in water none of which are nice in a fish tank. once its produced it is evaporated and you are left with dry powder bicarb
as its a salt, sodium bicarbonate, it will also raise your total disolved solids (not good) and raise the carbonate hardness, bicarbonate . its solubility: 7.8g/100g water at 18 deg C
when the water evaporates it will leave the bicarb in the water, ever been to a swimming pool at opening time and seen the white staining on the poolside??
once added you can only dilute to remove it, remember it is essentialy a salt!

there are better ways to raise the Kh and Ph as hwat we are all trying to achieve is balanced water

think of it this way.....
the sea is salty so we add salt to the tank, the sea has sand which it crushed coral/shells so we put coral substrate in, there is algae and seaweed so we put that in.... basicaly we mimic the natural way the sea is. in fresh water look at the fish you want and find out about thier natural habitat and mimic it. mot many fish have the money to buy bicarb so they make do with bogwood, limestone crushed freshwater shells ect. think about a long term solution not a quick fix

just my tuppence worth

 

[waterdrop]

once added you can only dilute to remove it

Right, so nearly all the dissolved baking soda used during a fishless cycle would be gone once you removed the bulk of the water at the end. Once you've determined that ammonia and nitrate are being processed to 0ppm within 10-12 hours or less and waited a week to make sure no more surprise spikes show up, you can go ahead and siphon off all the water, leaving perhaps the water in the external filter. At that point most traces of the bicarb would be gone and I agree, you wouldn't put it back in to an aquarium that has fish.

..would be interesting to hear why TwoTankAmin, after 6 months of using some crushed coral, decided the danger of CO2 dropping his pH too much was not there enough to justify continuing with the coral...

 

[monkey_biz]

crushed coral or crushed sand is essentialy calcium carbonate which if mixed with acid produces co2 (co2 also being an acid!!!!)
and Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate.
water chemistry is complicated, you add something to solve one problem and you can create 3 new problems.
keep it basic and copy nature or you will be playing with calculations like this CaCO3 + CO2 + H2O → Ca(HCO3)2

 

[waterdrop]

UPDATE: I am still fishless cycling this tank, waiting for the Nitrite-Oxidizing-Bacteria to be able to process my Nitrite spike down to zero within 10 hours. Its a 28G/106L and I had put 1.5 teaspoons of baking soda in, which raised my KH from 0 to 3 or 4 KH. This allowed my pH to hold at about 7.4 for several days, but eventually the KH dropped and the pH dived to 6 or below.

I did a complete water change (except for water in external filter), bringing my pH back up to 7.5. This time I added two slightly rounded teaspoons of baking soda and measured KH to be 5. This has been holding my pH up at 7.5 for even more days, despite steady build-up of Nitrates.

[Another science question: I've not seen any written claims that solids related to the baking soda will precipitate out or attach or in any way stay with the filter and tank after this fishless cycling is over with. (I see this to be another small scientific question, thus not just my little newbie fishless cycling question! Anyone?) Once the second bacteria (the slower to develop NOB) are sufficient enough to rapidly drop nitrites to zero, I plan to do probably more than one 100% water change prior to stocking - thus I anticipate the TDSs (with whatever the baking soda added) to be greatly diluted. If anyone disagrees (monkey_biz is doing a good job telling me some of the chemistry, anyone else even reading this??).. anyone disagrees, please tell me.]

[Background on why I'm bothering: I'm trying to be a bit of a guinea pig for some of the fishless cycling details here! I suspect that the experienced aquarists here on TFF justifiably don't get much experimental time with it because they always have mature media available for cloning. I think rdd1952 has done some fishless runs on purpose rather than use mature media, to verify the process, but that seems to be the extent of the experimentation I've found reading on.]

Your humble, curious old newbie dad, ~~waterdrop~~

 

[monkey_biz]

hi there
yes you are right, anything you have added un-naturaly to the water will be diluted out. bicarb is awful stuff (i use about 200 kg every week of the stuff) it sticks to and coats everything so when you do a 100% water change you will only get rid of about 80% of the stuff....... then you add more with the new water but the ammount you added will be different to what you put in originally because of the residue and so on........

so the crushed coral is really the better option as it slowly increases the levels and you only have to wash it Thoroughly every time you clean the filter as you dont really want the bacteria to grow on it as its quite porous and will become clogged with detrious and dead bacteria and become a nitrate generator. i scrub mine in cloronated tap water and soak it for a few days (i have 2 bags full) then let it dry out completely before the next filter clean

but thats just my opinion and it works for my tanks, it may not work for yours
its all trial and error but interpolating the information from other users try it all and stick to what is easiest, remembering it will be a regular thing for YEARS, and most natural.
thats the thing about fishkeeping, there is always something to learn. none of us knows everything but together we have a wide knowledge base. im strong on water chemistry as a base line (its my job) but types of fish and compatabilities..............? i keep one tank of various livebearers and 2 bolivian rams the other neons and soon to be shrimps, i just like the look of brightly couloured fish

 

[Colin_T]

Coral rubble, crushed coral, limestone, shells, shell grit and coral sand are all calcium carbonate. They all work in the same way.
Lots of people have a section in their canister filter with shell or coral rubble and this helps stabilise the PH and increase the hardness a bit. Other people use pieces of limestone rock as ornaments in the tank. It does the same thing.
Over time the limestone, shell, coral, etc dissolve as they neutralise the acids in the water. This means over the course of a year or two the amount of limestone, shell, etc will be reduced and eventually you will have to add more to keep the PH and hardness up.