Crushed coral in filter

[Cinnebuns]

Due to my tap water containing nuts and bolts, I have only very briefly ever used crushed coral. I found a need for it recently in one of my tanks. I'm hoping to put it in the filter. It is an aqueon 20. Can I just put the bag in the open area to the left or will that create problems?  I hope I don't have to get rid of some media to fit it in. 

[Fish Folk]

Yes. That space should work fine as long as it's not applying too much pressure on the u-tube, blocking the overflow, pushing out the seal ring, etc.

Here's a good look at the AquaClear HOB design, with some helpful instructions for proper maintenance (which most of us do well to review from time to time.)

As I understand it, Crushed Coral should slowly raise your KH -- Carbonate Hardness -- sometimes referred to as "temporary hardness" because it will break down over time, leading to pH lowering. Adding Crushed Coral should, in theory, stabilize your pH. The crudest way to think of this is the old Volcano kid's science fair project: Acid + Baking Soda. Either Vinegar or Lemon juice reacts with sodium bicarbonate to achieve a neutral solution. On a much more complex scale, the carbonates (or bicarbonates) in water will keep natural numb acids that develop from plant decay from drawing down you pH. 

GH, on the other hand, is measuring calcium and magnesium. It's a measurement of these dissolved metals. Plants will benefit from and absorb both of these as nutrients from the water column. 

[TeeJay]

I have used crushed coral both ways. In my hob and mixed in with gravel. I find mixing with gravel is easier and one less thing to worry about in my hob. Especially since I just like to run all sponges in my filters.

The only downside to mixing it with the substrate is it takes longer to dissolve to get a better kh buffer going. But I'm the long run way less to worry about. 

I have 0 kh out of my tap water so all my tanks have it since they all have snails and or shrimp in them. I just test the kh every few weeks to make sure it stays up. Over time as it dissolves your kh will lower and you will need to add more. About 1 pound per 10 gallons keeps me at a kh of 4-6 

[nabokovfan87]

On 7/1/2023 at 7:12 PM, Fish Folk said:

Yes. That space should work fine as long as it's not applying too much pressure on the u-tube, blocking the overflow, pushing out the seal ring, etc.

Aqueon's have the pump in the tank and it goes up into that section, then left to right.

It should be perfectly fine to use the space (or put it in the chamber on the right) as long as you keep an eye out for something like detritus building up and raising the water level.  As long as it doesn't splash, displace too much water in the chamber, or clog --> flood then you're ok.

[Fish Folk]

On 7/2/2023 at 3:14 AM, nabokovfan87 said:

Aqueon's have the pump in the tank and it goes up into that section, then left to right.

It should be perfectly fine to use the space (or put it in the chamber on the right) as long as you keep an eye out for something like detritus building up and raising the water level.  As long as it doesn't splash, displace too much water in the chamber, or clog --> flood then you're ok.

Ah! I totally misread. Aqueon is not AquaClear. But you’re right. Shouldn’t be an issue.

[Cinnebuns]

On 7/1/2023 at 11:27 PM, TeeJay said:

I have used crushed coral both ways. In my hob and mixed in with gravel. I find mixing with gravel is easier and one less thing to worry about in my hob. Especially since I just like to run all sponges in my filters.

The only downside to mixing it with the substrate is it takes longer to dissolve to get a better kh buffer going. But I'm the long run way less to worry about. 

I have 0 kh out of my tap water so all my tanks have it since they all have snails and or shrimp in them. I just test the kh every few weeks to make sure it stays up. Over time as it dissolves your kh will lower and you will need to add more. About 1 pound per 10 gallons keeps me at a kh of 4-6 

The reason I don't want to mix it in the substrate is I need to be able to easily remove it all eventually. This won't be permanent for this tank. 

[Galabar]

What is the purpose of the crushed coral?

 

[Cinnebuns]

On 7/4/2023 at 8:51 PM, Galabar said:

What is the purpose of the crushed coral?

 

Increases kh and subsequently ph. Will also raise gh.