High PH/Hardness and growing plants

[Fenrir]

Backstory: live in WI where water is fairly hard. Ph sits at 8.0, gh is high and kh is also around 150ppm out the tap after sodium water softener. 

I set up a 210 gallon aquarium with a 40 gallon sump. Had crushed coral sand(mistake) and a mix of red granite gravel and volcanic planted substrate. And installed 2x 48" fluval 3.0s. With injected c02 via inline diffuser. Specific plants thrived! But most stem plants even when floated for 3 weeks would just melt after being put in my aquarium. I did numerous amounts of testing and found that in my tank my Gh was at well over 300 ppm.

Present:

I have now installed a rodi water system and removed all but a half pound of the crushed coral sand and added 60lbs of eco complete black aqua soil to the tank. I've done close to 40 to 50 gallons of water changes now removing old water and putting in pure rodi water. After testing it looks like the ph has dropped to 7.6, kh is at 120ppm but GH won't change and is still holding at over 300ppm. I don't know if I am fighting a losing battle or if I need to add tannins to the water to help in dissolving some of that gh.

I want more flexibility in what I plant in my tank. And hard water I feel is my culprit what are some thoughts on this?

[Whitecloud09]

On 1/31/2024 at 12:32 PM, Fenrir said:

Backstory: live in WI where water is fairly hard. Ph sits at 8.0, gh is high and kh is also around 150ppm out the tap after sodium water softener. 

I set up a 210 gallon aquarium with a 40 gallon sump. Had crushed coral sand(mistake) and a mix of red granite gravel and volcanic planted substrate. And installed 2x 48" fluval 3.0s. With injected c02 via inline diffuser. Specific plants thrived! But most stem plants even when floated for 3 weeks would just melt after being put in my aquarium. I did numerous amounts of testing and found that in my tank my Gh was at well over 300 ppm.

Present:

I have now installed a rodi water system and removed all but a half pound of the crushed coral sand and added 60lbs of eco complete black aqua soil to the tank. I've done close to 40 to 50 gallons of water changes now removing old water and putting in pure rodi water. After testing it looks like the ph has dropped to 7.6, kh is at 120ppm but GH won't change and is still holding at over 300ppm. I don't know if I am fighting a losing battle or if I need to add tannins to the water to help in dissolving some of that gh.

I want more flexibility in what I plant in my tank. And hard water I feel is my culprit what are some thoughts on this?

Can you gimme a pic of the tank + what are the plants in the tank?

[Tony s]

In Indiana here, same water. Haven’t had any issues with plants. Most plants prefer the hardness. More calcium and magnesium. I only went to RO water because we have iron bacteria in the well. It turns everything it touches (and I mean everything including grass) rust red. That said I’m sure there’s something I can’t grow, but haven’t found it yet. 

[Whitecloud09]

I have had the opposite issue with my gh @Fenrir, so wanted to see what was going on here.

Edited January 31 by Bigdog99

[jwcarlson]

You probably need to change another 150 gallons of water.  If you don't have fish in it and the plants allow, you could drain it mostly empty and slowly fill it up with the water you want (assuming you are making batches of water) as it's available.  You probably don't need to go full RODI, can probably get away with just RO.  But I'm not a plant expert.  I, too, have exceedingly hard water and I've just embraced whatever grows in the water I have and if it dies, it dies.  Of course that all depends on your goals.

Edited January 31 by jwcarlson

[Whitecloud09]

On 1/31/2024 at 12:42 PM, jwcarlson said:

You probably need to change another 150 gallons of water.  If you don't have fish in it and the plants allow, you could drain it mostly empty and slow it up with the water you want (assuming you are making batches of water) as it's available.  You probably don't need to go full RODI, can probably get away with just RO.  But I'm not a plant expert.  I, too, have exceedingly hard water and I've just embraced whatever grows in the water I have and if it dies, it does.  Of course that all depends on your goals.

Yes you are right 

[Tony s]

On 1/31/2024 at 12:42 PM, jwcarlson said:

You probably need to change another 150 gallons of water.  If you don't have fish in it and the plants allow, you could drain it mostly empty and slowly fill it up with the water you want (assuming you are making batches of water) as it's available.  You probably don't need to go full RODI, can probably get away with just RO.  But I'm not a plant expert.  I, too, have exceedingly hard water and I've just embraced whatever grows in the water I have and if it dies, it dies.  Of course that all depends on your goals.

And that's the best way to do it. you can drive yourself nuts trying to chase ph  gh  kh. with the exception if you want to keep sensitive species. but there are alternatives to those as well

[jwcarlson]

On 1/31/2024 at 12:08 PM, Tony s said:

And that's the best way to do it. you can drive yourself nuts trying to chase ph  gh  kh. with the exception if you want to keep sensitive species. but there are alternatives to those as well

Everything I have ends up in my tap water unless I am trying to breed it.  And the stuff that actually breeds just does it in my tap water and I've failed miserably at breeding anything in tailored water. 😄  And it's a pain in the butt to manage the different types of water.  

[Tony s]

I've seen apistos, severum, geophagus. oscars in hard water. not for breeding. but, unfortunately no rams or discus.

[jwcarlson]

On 1/31/2024 at 12:16 PM, Tony s said:

I've seen apistos, severum, geophagus. oscars in hard water. not for breeding. but, unfortunately no rams or discus.

My discus are in my tap water.  pH 8.3, GH and KH are each like 18+ degrees.  Not breeding in this, just keeping.

Edit to add my actual GH/KH, which I haven't checked for awhile.  This is from a couple years ago... KH was 16 drops = 286 ppm, GH was 18 drops = 322 ppm

Edited January 31 by jwcarlson

[Tony s]

On 1/31/2024 at 2:13 PM, jwcarlson said:

My discus are in my tap water.  pH 8.3, GH and KH are each like 18+ degrees.  Not breeding in this, just keeping.

Edit to add my actual GH/KH, which I haven't checked for awhile.  This is from a couple years ago... KH was 16 drops = 286 ppm, GH was 18 drops = 322 ppm

Very cool. My wife really wants a discus tank. I’ve been trying rams first, and failing 

[jwcarlson]

On 1/31/2024 at 1:55 PM, Tony s said:

Very cool. My wife really wants a discus tank. I’ve been trying rams first, and failing 

I just got my first rams a few weeks ago.  So no opinions yet. 😄