I’ve made an amateur mistake!

[AmyKieran]

I bought most of the rock on my recent post from someone on Facebook that had it in his marine tank. He told me that if I boiled it it would be okay. I’ve put it in my tank and overnight lost 17 fish I’ve removed all the fish and put into quarantine tanks. I’ve drained the entire tank, cleaned gravel, glass and replaced with clean water with a bottle of colony nitrifying bacteria. I’ve put back in the remaining fish and they seem to be doing okay. Now I do want rocks in my tank but I’m now scared. I’ve been told to go to the beach and collect rocks there for my tank. I’ve been told to keep alternating between boiling and putting them in sunlight for about a week before putting in my tank and ensure I get the rocks as far away from the water as I can. Do you think this will be okay or should I refrain from doing this too?


Ps I have a Malawi freshwater tank

Thanks
Kieran

 

[mbsqw1d]

Was the tank cycled? Did you measure nitrogen levels, ammonia, nitrite & nitrate?

 

[AmyKieran]

Was the tank cycled? Did you measure nitrogen levels, ammonia, nitrite & nitrate?

Yes I measured all of above as well as tank being cycled. Nitrite was 0 nitrate was 30 ammonia 0.3 and phosphates were 3 which was the only really worrying value

 

[GaryE]

The surface of rock says a lot. If it's porous, avoid it. But before going to the beach (where I get all the many rocks I use) I've taken to looking up what the rocks are, in a field guide, so I don't get something that will leach minerals. In your case, if it was live rock, it may have been dead matter in the rocks from the marine tank that tipped things over.

 

[AmyKieran]

The surface of rock says a lot. If it's porous, avoid it. But before going to the beach (where I get all the many rocks I use) I've taken to looking up what the rocks are, in a field guide, so I don't get something that will leach minerals. In your case, if it was live rock, it may have been dead matter in the rocks from the marine tank that tipped things over.

I’m looking at filling my tank with very flat rocks and stacking them. What rules of thumb should I be following for those types of rocks?

 

[GaryE]

Slate is really good if you can find it.

 

[Colin_T]

What sort of fish are in your tank?

Most rocks in marine tanks are limestone or sandstone and are calcium based. They will raise the pH of your water well above 7.0 and can take the pH up to 8.5. If you have any ammonia in the water at a high pH, you can quickly kill the fish.

Rocks from a marine tank should be fine to use in a freshwater tank if the fish require a pH above 7.0. However, the rocks must be free of marine organisms that have grown on the rocks otherwise these organisms will die when put in freshwater. If they die they will release ammonia and the combination of ammonia and high pH will kill the fish.

There won't be any diseases transfered from a marine tank into freshwater bcause the disease organisms can't survive going from salt to fresh or vice versa.

If you want to use rocks for an aquarium, soak them in a bucket of freshwater for a few weeks and change the water each day. You can hose them off too. If the rocks don't smell bad or cause the water to change colour, remove them and rinse, then allow them to dry. Then put them in the tank.

As a general rule, cream or white rocks will be calcium based and raise the pH. Darker coloured rocks (black or brown) won't normally change the pH of the water. You can also test rocks for calcium by pouring some white vinegar on the rock when the rock is dry. If it fizzes and foams up, the rock is calcium based and will raise the pH of the water. After you have done the vinegar test, rinse the rock off to remove the vinegar and then use the rock if you want to.

 

[AmyKieran]

What sort of fish are in your tank?

Most rocks in marine tanks are limestone or sandstone and are calcium based. They will raise the pH of your water well above 7.0 and can take the pH up to 8.5. If you have any ammonia in the water at a high pH, you can quickly kill the fish.

Rocks from a marine tank should be fine to use in a freshwater tank if the fish require a pH above 7.0. However, the rocks must be free of marine organisms that have grown on the rocks otherwise these organisms will die when put in freshwater. If they die they will release ammonia and the combination of ammonia and high pH will kill the fish.

There won't be any diseases transfered from a marine tank into freshwater bcause the disease organisms can't survive going from salt to fresh or vice versa.

If you want to use rocks for an aquarium, soak them in a bucket of freshwater for a few weeks and change the water each day. You can hose them off too. If the rocks don't smell bad or cause the water to change colour, remove them and rinse, then allow them to dry. Then put them in the tank.

As a general rule, cream or white rocks will be calcium based and raise the pH. Darker coloured rocks (black or brown) won't normally change the pH of the water. You can also test rocks for calcium by pouring some white vinegar on the rock when the rock is dry. If it fizzes and foams up, the rock is calcium based and will raise the pH of the water. After you have done the vinegar test, rinse the rock off to remove the vinegar and then use the rock if you want to.

I see, I am keeping Malawi cichlids. I can’t afford buying rock from aquatic shops as it’s very expensive. Would you personally reccomend getting rocks from the beach? If so what process should I do to treat the rock ?

 

[Colin_T]

Limestone and sandstone is ideal for Lake Malawi or Lake Tanganyikan fishes because it increases pH and these fish naturally occur in water with a high pH (7.6-9.0).

You can collect limestone and sandstone from the beach and it is usually safe. Don't collect rocks from areas with lots of boats or in/ near a harbour because there can be an oily film on the water caused by fuel from the boats.

Avoid rocks that have bird poop or things growing on them. Get dry rock from above the water line.

When you get the rocks home, rinse under tap water and add them to the tank.

Don't collect rocks from national parks because you get done for mining in a national park.

Some councils get upset if you take rocks from thier beach so try to do it when nobody is around.

 

[AmyKieran]

Update -

I have decided to, instead of taking further risks, just order 25kg of ocean rock from an aquatics shop. I got the ocean rock for £52 delivered in UK if anyone else is looking for a good price for ocean rock

Thanks