The Ph Balancing Act

[Shifty1303]

heya guys!
 
cycling a 200l at the moment however today the pH dropped from 7.0 to 6.4 in 24 hours! is this a result of cycling or is it due to the bogwood i have in my tank? can see the wood in the attached picture which ive grown fond of so id rather not get rid of it. however if it is responsible for dropping my pH too much from the tap water levels of 7.4 then ill do whats right and ditch it for a smaller piece. alternatively can i add something alkaline to the tank like coral sand etc to balance it out?
 
thanks for any replies
 
* an aside - rather than posting a whole other topic i thought id quickly ask re cycling if im nearly done. getting 3ppm of ammonia down to 0ppm ammonia and only 0.25ppm of nitrite in 24 hours now but has been doing this consistently for a week. is it stalling at this level or will it just one day read 0ppm nitrite and ill be done? im on day 31 of my cycle with fairly consistent pH around 7.0 (minus today) and temps at 28C. cheers!

 

[Byron]

On the pH issue, it is a bit complex.  First, what is the GH and KH of your tap water?  These are tied to the pH.  You don't need a test, just ascertain from the municipal water authority what the GH (general hardness) and KH (carbonate hardness or Alkalinity) are.
 
Second, what fish do you intend keeping?  Many will be ideally suited to a slightly acidic pH.  It is better to select fish that are suited to your water parameters rather than attempting to adjust the parameters.  The latter can get complicated and costly, and cause several problems.  And a stable set of parameters is better for the fish than fluctuating parameters.
 
The wood will naturally tend to lower pH, but this is largely dependent upon the GH and KH as the latter in particular buffers the pH to some extent.  And the pH of your tap water is presumably 7.4, but when you tested it did you out-gas the CO2 first?  You can do this by letting a glass of tap water sit 24 hours before testing, or more quickly by vigorously shaking some tap water for several minutes prior to testing it.  This out-gassing is not needed for aquarium water, just fresh tap water.  This will give you a more reliable result.
 
Another factor is the cycling, if you are adding ammonia.  I believe this can affect the pH.  I've never "cycled" an aquarium per say, relying on natural bacteria and live plants to do the task, so I cannot explain this but I mention it.
 
Byron.

 

[Shifty1303]

On the pH issue, it is a bit complex.  First, what is the GH and KH of your tap water?  These are tied to the pH.  You don't need a test, just ascertain from the municipal water authority what the GH (general hardness) and KH (carbonate hardness or Alkalinity) are.
 
Second, what fish do you intend keeping?  Many will be ideally suited to a slightly acidic pH.  It is better to select fish that are suited to your water parameters rather than attempting to adjust the parameters.  The latter can get complicated and costly, and cause several problems.  And a stable set of parameters is better for the fish than fluctuating parameters.
 
The wood will naturally tend to lower pH, but this is largely dependent upon the GH and KH as the latter in particular buffers the pH to some extent.  And the pH of your tap water is presumably 7.4, but when you tested it did you out-gas the CO2 first?  You can do this by letting a glass of tap water sit 24 hours before testing, or more quickly by vigorously shaking some tap water for several minutes prior to testing it.  This out-gassing is not needed for aquarium water, just fresh tap water.  This will give you a more reliable result.
 
Another factor is the cycling, if you are adding ammonia.  I believe this can affect the pH.  I've never "cycled" an aquarium per say, relying on natural bacteria and live plants to do the task, so I cannot explain this but I mention it.
 
Byron.

 
thanks for the response again byron

 
just tested the tank water and got a GH of 10 and a KH of 2

(when i last tested kH about 3 weeks ago it was 5). as for the tap water i got this screen shot from my water provider but wasnt sure which values were the ones used sorry!
 
i intend to keep corys (of which i have 8 in my existing tank i shall move over) and as per your own suggestion byron i am getting a shoal of black ruby barbs (10 or so). at a later date i wanted to add about 10 dwarf neon rainbows too. these choices were made around having an original pH without bogwood of 7.4 though.
 
i did not out gas the co2 so will leave a sample out now and post results tomorrow but the attached jpg should give you some idea of my water quality.
 
if you dont "cycle" do you think i can add fish soon if im processing the vast majority of the ammonia? surely 10 barbs for the first fortnight arent going to produce anywhere near 3ppm ammonia per day right?
 
thanks again!

 

[Gruntle]

Sounds to me like your cycle is almost complete. I had about a week at the end of mine where the ammonia would drop to 0 in 24 hours but the nitrite would stubbornly stay at 1ppm. One day very soon you'll get the magic 0-0 and you'll be done. Some would suggest another test after that is a good insurance policy, I was in a bit of a rush and lost some fish by adding them too early.
 
Very frustrating when the last bit of the cycle just won't seem to tick over, but within a month of having fish swim happily in your tank you'll forget all about it.

 

[Byron]

First to explain the numbers.  GH and KH can be expressed in different ways as you can see from the chart.  In the hobby, I believe most of us use either the degrees [dGH and dKH] or ppm (parts per million).  This ppm is the same as mg/l, so it is GH 145 ppm which is 8 dGH.  This is soft.  The KH they give is 85 ppm which equates with almost 5 dKH.
 
The GH and KH generally remain much the same but this may not be the case depending where your water comes from; different reservoirs may have different parameters, and sometimes the season can affect this too.  Heavy rains washing organics into the reservoir for instance can lower the GH and KH and pH too.  You own tests are pretty close that I wouldn't worry.  Which test are you using though?
 
As for the pH, let's see what the test tomorrow gives us.  With a KH somewhere around 3-5 dKH, there will be some buffering of the pH (buffering means the pH will tend to remain stable as it comes out of the tap) but other factors play into this too, such as the aquarium becoming biologically established which naturally tends to acidify so this will mix in at water changes.  Whatever happens here, you have no worries in my view, as the numbers are certainly not extreme and the fish are well suited to the ranges.  Most South American fish and most SE Asian fish occur in very soft water with an acidic pH.  Some such as those mentioned here would be OK with what you have, whether the pH is 7.4 or 6.4 so no issues there.  The Dwarf Neon Rainbows also occur in soft slightly acidic water, but most available today will be commercially raised and again can manage with slightly basic pH too.
 
BTW, with the dwarf rainbows, are you familiar with their temperament?  A group naturally as they are shoaling fish, but here it is best to have two females for each male to avoid over-harassment of the females.  So for example a group of 3 males and 5-6 females would be OK.  Sexual dimorphism is easy. Males have red edges on their fins whereas females have yellow or orange fins [although in the wild, most females appear to have red fins, but as I said, fish in stores will probably be tank-raised and not imported wild fish].
 
I don't want to mix you up on the cycling, so stay with what you planned.  I assume you are adding ammonia, and I would not start adding live plants with this as it can poison them.
 
Byron.

 

[Shifty1303]

Sounds to me like your cycle is almost complete. I had about a week at the end of mine where the ammonia would drop to 0 in 24 hours but the nitrite would stubbornly stay at 1ppm. One day very soon you'll get the magic 0-0 and you'll be done. Some would suggest another test after that is a good insurance policy, I was in a bit of a rush and lost some fish by adding them too early.
 
Very frustrating when the last bit of the cycle just won't seem to tick over, but within a month of having fish swim happily in your tank you'll forget all about it.

 
it is annoyingly stubborn yes! saying that i tested just a minute ago and nitrite was also zero me thinks im done but gonna run one more dose of ammonia to check.
 

First to explain the numbers.  GH and KH can be expressed in different ways as you can see from the chart.  In the hobby, I believe most of us use either the degrees [dGH and dKH] or ppm (parts per million).  This ppm is the same as mg/l, so it is GH 145 ppm which is 8 dGH.  This is soft.  The KH they give is 85 ppm which equates with almost 5 dKH.
 
The GH and KH generally remain much the same but this may not be the case depending where your water comes from; different reservoirs may have different parameters, and sometimes the season can affect this too.  Heavy rains washing organics into the reservoir for instance can lower the GH and KH and pH too.  You own tests are pretty close that I wouldn't worry.  Which test are you using though?
 
As for the pH, let's see what the test tomorrow gives us.  With a KH somewhere around 3-5 dKH, there will be some buffering of the pH (buffering means the pH will tend to remain stable as it comes out of the tap) but other factors play into this too, such as the aquarium becoming biologically established which naturally tends to acidify so this will mix in at water changes.  Whatever happens here, you have no worries in my view, as the numbers are certainly not extreme and the fish are well suited to the ranges.  Most South American fish and most SE Asian fish occur in very soft water with an acidic pH.  Some such as those mentioned here would be OK with what you have, whether the pH is 7.4 or 6.4 so no issues there.  The Dwarf Neon Rainbows also occur in soft slightly acidic water, but most available today will be commercially raised and again can manage with slightly basic pH too.
 
BTW, with the dwarf rainbows, are you familiar with their temperament?  A group naturally as they are shoaling fish, but here it is best to have two females for each male to avoid over-harassment of the females.  So for example a group of 3 males and 5-6 females would be OK.  Sexual dimorphism is easy. Males have red edges on their fins whereas females have yellow or orange fins [although in the wild, most females appear to have red fins, but as I said, fish in stores will probably be tank-raised and not imported wild fish].
 
I don't want to mix you up on the cycling, so stay with what you planned.  I assume you are adding ammonia, and I would not start adding live plants with this as it can poison them.
 
Byron.

 
thanks for the explanation byron! you have been an immense help these last couple of months.
 
I use API test kits for all parameters so pretty reliable!
 
the test of tank pH today gave me about 6.1 so its dropping even lower lucky the cycle appears to have just finished or a pH crash could ruin it no? as for the tap water i stood for 24 hours, it gave me a pH reading of near on 7.6.
 
i was aware of the sexual dimorphism with neon rainbows but wasnt totally aware of the male/female ratio so thanks for that! with the black ruby barbs i was planning on 3 males and 6/7 females. that sound appropriate?
 
thanks again both of you

 

[Byron]

The Black Ruby Barb, in my experience with two different groups, is OK in more of an equal mix; if 10 is the intended number, five of each sex will be fine.  And given the incredible beauty of the male, this allows you a couple more.  I currently have 7 males and 7 females plus a fry that hatched a couple of weeks ago (one egg obviously survived in the tangle of moss and hatched) and is being ignored by the adults.
 
I wouldn't worry over the pH now.  Once you are no longer adding ammonia, do a good water change and then add some live plants.  Floating are ideal because being fast growers they will take up a lot of ammonia, so the "cycle" isn't an issue then.  A few fish to start off, and you're set to go.
 
BTW, when acquiring shoaling fish like all those mentioned are, get the entire group at the same time when you can.  The fish will settle in better, and their hierarchy establishment will be easier.  Not so critical for the barbs or corys, but moreso for the rainbows.
 
Byron.

 

[Shifty1303]

The Black Ruby Barb, in my experience with two different groups, is OK in more of an equal mix; if 10 is the intended number, five of each sex will be fine.  And given the incredible beauty of the male, this allows you a couple more.  I currently have 7 males and 7 females plus a fry that hatched a couple of weeks ago (one egg obviously survived in the tangle of moss and hatched) and is being ignored by the adults.
 
I wouldn't worry over the pH now.  Once you are no longer adding ammonia, do a good water change and then add some live plants.  Floating are ideal because being fast growers they will take up a lot of ammonia, so the "cycle" isn't an issue then.  A few fish to start off, and you're set to go.
 
BTW, when acquiring shoaling fish like all those mentioned are, get the entire group at the same time when you can.  The fish will settle in better, and their hierarchy establishment will be easier.  Not so critical for the barbs or corys, but moreso for the rainbows.
 
Byron.

 
ah ok thanks a lot
 
well the tank is now cycled, i have done a 90% WC and there are plenty of plants in there. provided all is stable in the morning i will go pick up a shoal of either barbs or rainbows; perhaps rainbows this time considering your point as i feel adding a whole group will be more feasible now when the filter is biologically very strong vs when it settles to the level of existing fish.
 
do you have a recommendation of a good floating plant? never kept them before.
 
Shifty

 

[Byron]

Water Sprite (Ceratopteris cornuta, the best floating species of the two or three) is ideal.  Water Lettuce (Pistia stratiotes) is another, and there is Frogbit.  These three are true floating plants and develop interesting root systems that fish will browse for food, and in which they will spawn.  Some stem plants grow nicely floating; my favourite here is Brazilian Pennywort.  Then there are smaller plants like Salvinia, and of course duckweed; useful in some situations but here I would avoid these two as they are small and duckweed can be a nuisance for some.
 
Byron.