crushed coral in a planted aquarium

[GardenStateGoldfish]

Hey all!

I am wondering if crushed coral is detrimental in a planted tank? I know for the most part plants like softer water and I do have hard water, GH is around 300 ppm. But my KH is around 40ppm (3 drops on the api kit)  I have a very heavily planted tank and plants would consume the KH quickly causing the ph to drop. If I add crushed coral to the tank, will that harm the plants? Thanks!

[Eric R]

I don't see why it would, it will help stabilize the kh, which should be good for the plants.

[Travis]

I have a 1lb filter bag full of crushed coral in the filter of my heavily planted tank to help buffer the PH. I haven't noticed any problems with the plants. 

 

[KBOzzie59]

Black Moscow breeding tank.  Crushed coral, 2 shots of easy green per week.

[Mmiller2001]

A 2-3KH is excellent for a planted tank. Why raise it? How often do you water change? Have you tested KH after a water change and before a water change? Was KH 0 before the water change? What's the KH of your water source?

[GardenStateGoldfish]

8 minutes ago, Mmiller2001 said:

A 2-3KH is excellent for a planted tank. Why raise it? How often do you water change? Have you tested KH after a water change and before a water change? Was KH 0 before the water change? What's the KH of your water source?

KH of my water source is (3 drops on the API test kit) I am changing water once a week but sometimes the PH would drop before the once a week change, I would like to change less water, I am trying to build a hydroponic system on the tanks that will reduce the frequency I change water. close to 700 gallons of water so I would like to use much less water, I always do water changes into the yard but still I can't capture all the waste water to where I would want it. If I can reduce the frequency of WC's I can use the waste water much more efficiently. The reason to raise it would be to extend the time between water changes. 

[Mmiller2001]

9 minutes ago, GardenStateGoldfish said:

KH of my water source is (3 drops on the API test kit) I am changing water once a week but sometimes the PH would drop before the once a week change, I would like to change less water, I am trying to build a hydroponic system on the tanks that will reduce the frequency I change water. close to 700 gallons of water so I would like to use much less water, I always do water changes into the yard but still I can't capture all the waste water to where I would want it. If I can reduce the frequency of WC's I can use the waste water much more efficiently. The reason to raise it would be to extend the time between water changes. 

A pH drop is not a problem at all. Test your KH right before your water change. I bet it will be mostly unchanged. I think people are over estimating how quickly KH might drop.

I keep my tanks at 1.5KH, I hit a pH of 6.1 with CO2 injection. When I test KH, prior to my water change, my KH is 1.5. 

My recommendation would be, if you want to reduce water changes, is monitor TDS. Get a baseline after a water change. If TDS goes up by 100, change water. I would grab some potassium carbonate, do weekly KH test, and if KH drops, dose the potassium carbonate to the tank to maintain 3dKH.

 

[GardenStateGoldfish]

52 minutes ago, Mmiller2001 said:

Test your KH right before your water change.

Sorry I forgot to mention, it is 1 drop when I tested it from the tank. (KH) I also don't own a TDS meter but I assume my TDS will be fairly high since the GH is 300 ppm.

Thanks for the advice though, I guess I will just ignore the KH then. 

 

Edited April 25, 2021 by GardenStateGoldfish

[Mmiller2001]

36 minutes ago, GardenStateGoldfish said:

Sorry I forgot to mention, it is 1 drop when I tested it from the tank. (KH) I also don't own a TDS meter but I assume my TDS will be fairly high since the GH is 300 ppm.

Thanks for the advice though, I guess I will just ignore the KH then. 

 

Don't ignore it, just check it before your water change so you learn your baseline. Then you can just add potassium carbonate to boost it if you want to extend water changes.

I recommend a TDS checker if you want to push your water changes out. It's a great tool to have and they are cheap.