Adding Minerals To Tank?

[Mitch_ScruffyCityAquatics]

I have a 75 gallon community tank with Mollies. I have been told it is best to supplement the tank with something like Wonder Shells to make sure the livebearers and plants have a happy life. 
 

I have hard water, but I have never tested it. I think I am going to try adding Wonder Shells to my tank, but I was curious how you tell if your minerals are in a healthy range or not? Is Wonder Shell so great that it’s best to add one every few weeks and forget about it? Or should I test my water? 
 

I would rather my tank inhabitants and plants have their beat life, but I don’t want to throw money at the tank if it doesn’t need it. Or maybe I just prefer to spend the money on something else for the tank. Haha. 

[MJV Aquatics]

Unless you have really soft water (seems not to be the case) you really don't need to add minerals as long as you do routine periodic partial water changes. All plants and fish use minerals, so in addition to removing pollutants with dilution, partial water changes replenish necessary minerals in the water. Speaking of replenish, for those with softer water, Seachem Replenish may be a good choice. Also, crushed coral would help with really soft water. (I'll confess that I've never used wondershell, but my water is neither hard nor soft).

[lefty o]

with hard water, you likely have plenty of minerals. however without specifically testing you dont really know the makeup of it. if you were to test the water for its exact mineral content , then you could target anything that is specifically lacking. short of that, you would probably be adding more of what you already have.

[Mitch_ScruffyCityAquatics]

That was my thoughts as well. Plus I am supplementing my fish’s diets with Vitachem. I have been losing some mollies lately. About one a week for the past three weeks. No issues noticed, just finding them floating in my water sprite the past three weeks. One was a fully mature male that has fathered the majority of my current mollies. 
 

I know when I have had Molly questions in the past people have said to add minerals for livebearers. What is the best way to test my water to find out what minerals I have?

[Mmiller2001]

Test GH and KH. API sells a kit with both. It's good enough and cheap.

[Mitch_ScruffyCityAquatics]

2 hours ago, Mmiller2001 said:

Test GH and KH. API sells a kit with both. It's good enough and cheap.

I ordered a test kit. Once I get it and have results I’ll post. 

[Mitch_ScruffyCityAquatics]

I just tested the aquarium. 
 

KH - 7-8 degrees Looks within reason. May explain why I’ve had issues with neons in the past. 
 

GH - 13 degrees. Seems high....

[Mitch_ScruffyCityAquatics]

So, I’m thinking I’ll return the wonder Shell. 🤣

From what I’ve read online I could buy another test for calcium, but I think I can watch my plants for signs of deficiency. If I am reading this right, my mollies do not need additional minerals. 

[gardenman]

As is often the case in fish keeping, nothing is as simple as it seems. While it's true that plants use up minerals in the water, fish food (at least the commercially available stuff) tends to have minerals included at a surplus level so the fish poop helps to remineralize the water.  Whatever the fish's bodies don't absorb gets pooped out. Also when water evaporates, just the water leaves and the minerals remain behind, so just topping off a tank can end up giving you a higher overall, long term level of minerals in the water than a water change. With a water change you might be removing water that's more mineral rich due to evaporation than the water you're replacing it with.  Gravel, sand, rocks, decorations, all can also add minerals to the water depending on what they're made of and to some extent the pH of the water.  A more acidic pH might leach more minerals from certain rocks/substrates. Plaster ornaments (not unheard of) can leach all kinds of stuff. Like I said, nothing is as simple as it seems.

 

[Mitch_ScruffyCityAquatics]

True, I do understand that. 

My pH is 7.6-8 

I don’t top off my water. And most weeks I do a 15-20% water change. I’ve been toying with the idea of skipping weeks because my nitrates are so low, and that is one of the reasons I am trying to determine what is in my water. I plan on testing my tap water today. I simply ran out of time yesterday. 
 

My original concern was that I thought I had hard water, but I wanted to be sure because I want to give my tank inhabitants their best life. I’ve now tested and I do have hard water. It looks like adding something like Wonder Shell would not be beneficial to my setup. Unless my tap water is drastically different (unlikely?) and water changes could be causing issues every week. 

Edited March 11, 2021 by Mitch Norton

[Mitch_ScruffyCityAquatics]

With those readings, Magic Shell would not benefit me, right?

[Mmiller2001]

35 minutes ago, Mitch Norton said:

With those readings, Magic Shell would not benefit me, right?

I don't think so, seems like your water is pretty close to what they like. But I'm no hard water expert.