question: KH and PH relations

[hangyong]

Hi All,

I am new to planted tank and this forum, so please forgive me if I ask some stupid questions.

I read somewhere that low KH can introduce PH fluctuations.

However, the tap water in Singapore has a KH near to ZERO.

My 4x2x2 tank has some plants in them, not sure what they are actually, maybe someone can help me ID them as well? Anyway, I have Co2 injected at about 1.5bps and has 4x54W T5HO with a Eheim 2076 canister filter. And I have about 60 Cardinal Tetras, and some guppies in it.

The PH is 6 and the KH is 1.

Just wondering, is it necessary that I make the KH higher to about 4-5 and maintain the PH at about 6.5?

Will it affect the Cardinals if I up the PH/KH that much (since they would prefer more acidic water)?

Will it affect the plants if I do not up the PH/KH that much?

Please advise which is the best balanced solution.

[PeterGwee]

Use a dropchecker since you are using a peat laden substrate. If you use a pH test pen, you can use it as a relative value to the dropchecker when it is in the good colour range and target that for the entire photo period especially 1/2 to an hour in when the lights are on and the rest of the day. Use a point outlet for your filter instead of the spraybar and point it slightly downwards and get the CO2 diffuser in the path of the current such that it will make it around the tank well.

Regards,
Peter Gwee

[FishSoup]

As for the plants.. the grass-like bunches should be Blyxa japonica, while the green stem plants in the last picture should be Tonina fluviatalis.

Don't know about the rest

[torque6]

Sorry to burst your bubble, but tank looks new from the the very "clean" eheim pipes, probably a new setup with minimum cycling efforts. Fishes are overstock in a densely planted tank.

[hangyong]

Use a dropchecker since you are using a peat laden substrate. If you use a pH test pen, you can use it as a relative value to the dropchecker when it is in the good colour range and target that for the entire photo period especially 1/2 to an hour in when the lights are on and the rest of the day. Use a point outlet for your filter instead of the spraybar and point it slightly downwards and get the CO2 diffuser in the path of the current such that it will make it around the tank well.

Regards,
Peter Gwee

Hi Peter,

thanks for the advise.

May I ask why change the spray bar to a point outlet?

would just moving the diffuser to the path of the current work as well??

[hangyong]

As for the plants.. the grass-like bunches should be Blyxa japonica, while the green stem plants in the last picture should be Tonina fluviatalis.

Don't know about the rest

Thanks for the ID!

[hangyong]

Sorry to burst your bubble, but tank looks new from the the very "clean" eheim pipes, probably a new setup with minimum cycling efforts. Fishes are overstock in a densely planted tank.

Hi Torque6,

you are right that the tank is new. Infact, its only gone through cycling for 3 weeks.

Do you mean that I have too many fishes and too many plants? sorry I dun really get the logic of the last sentence.

sorry for my ignorance.

[jacian]

60 tetras in a 4x2x2 tank is fine, no worry for that.

[torque6]

almost 3 weeks should be fine, you should be heading to your end of your cycling period in another week or so.

[hangyong]

added some coral chips to the canister filter and now the PH is about 6.0~6.5, and KH is about 2~3.

I just tested the tap water, and realised that the KH is 3.

Any idea why is it lower in the tank?

Anyway, now CO2 level is stable as the drop checker is showing green with about 2bps.

Also added 2 oto to suck up the brown algae...

[torque6]

wow, you tapwater is KH3. Which area are you at, eastside tapwater is usually 0.

[Jervis]

Emm... KH3 is a high for tap water... we usually get less than 1dkH.

[hangyong]

wow, you tapwater is KH3. Which area are you at, eastside tapwater is usually 0.

I stay near NTU, on the extreme West of Singapore.

I use the Sera test kit to test for KH, and it needs 3 drops for the solution to turn yellow.

First drop blue, second drop green, then 3rd drop yellow.

[hangyong]

Emm... KH3 is a high for tap water... we usually get less than 1dkH.

I realised too.... wonder whats wrong.. is that bad for health?

[torque6]

I stay near NTU, on the extreme West of Singapore.

I use the Sera test kit to test for KH, and it needs 3 drops for the solution to turn yellow.

First drop blue, second drop green, then 3rd drop yellow.

Its not wrong to have 3dkh water, just that you water should have relatively high PH. maybe >7.8 or so.

[hangyong]

Its not wrong to have 3dkh water, just that you water should have relatively high PH. maybe >7.8 or so.

hmm... let me check on that tonight.... have not tested tap water's PH actually...

[hangyong]

Its not wrong to have 3dkh water, just that you water should have relatively high PH. maybe >7.8 or so.

hey, just tested the tap water.... and its 7.5 thereabouts... wow... din know I have such hard water here....

[newtank]

HangYong,

I was wondering how you manage to drop your PH to 6.0 with just 1.5 bps of CO2? maybe the low KH contributed to this, I am currentl;y dosing about 4 bps with a KH of 4 and the PH normally hover around 6.4 to 6.6.

It is well documented that low KH will allow PH to fluctuate.

[hangyong]

HangYong,

I was wondering how you manage to drop your PH to 6.0 with just 1.5 bps of CO2? maybe the low KH contributed to this, I am currentl;y dosing about 4 bps with a KH of 4 and the PH normally hover around 6.4 to 6.6.

It is well documented that low KH will allow PH to fluctuate.

I added Coral Chips...

actually, the tank water was <6PH earlier....

I cut the CO2, but that did not bring the PH up much...

So I added the Coral Chips, and it went to between 6.0-6.5PH

Introduced CO2 again, but that did not lower the PH any lower as well...

now providing about 3bps of CO2, PH6.0-6.5, KH=2

[torque6]

yup coral chips helps to maintain PH in presence of a low KH.