Inert substrate for cherrys

[Trav80]

Hi all,

I'm setting up a new 3 foot tank for my cherrys (red & yellow), and picked up 40kgs of midnite black 2mm gravel. I was told by the guy at the shop it was inert and he uses it for multiple tanks with ph ranging from 5.5 to 8.5.

I thought I was being smart and tried to placing it in the tank without washing it and using bags to cover it ala benibachi / shrimps and style so it would not cloud up to much. That seemed to work but the gravel was not black it was brown but the tank was clear the next morning. I tested the ph a couple of says ago and it was 8.9, my tap water is only 7.3.

I decided to give it all a good wash, took me 2.5 hours and now it is black but once the tank was refilled the ph was still sitting very high at 8.5.

Is midnite black gravel really inert or am I doing something wrong?

[Matt_95]

Many black substrates will raise the PH, do you have anything else in the tank?

[Trav80]

Nope, just the midnite black 2mm gravel.

[Dean]

that PH is crazy high mate, especially for black gravel. are you sure your ph pen is calibrated correctly?

is there any white in it at all?

[Trav80]

I'm picking up some ph4.01 & ph7.01 calibration solutions on my next day off just in case, but I did check it against the API ph and high range ph test kit. So I'm sure it's ok, just needs to be calibrated lower as it takes a fair while to get a solid reading as it was calibrated with ph10 solution at the factory.

There isn't much white pieces in the substrate at all, it's mostly black and brown/red. I have left the tank empty so in a few days I will give it another good wash just incase it's the dust/dirt in the soil.

[Foxpuppet]

Where are you going to get your calibration solution?

[Trav80]

I'm getting it from the manufacturer, Hanna Instruments. They are only 15 minutes from me. I think they said a 500ml bottle was around $25 or so, I was going to get them from overseas but the shipping would make it to expensive.

[Trav80]

Have now washed the gravel so many times that I have lost count. PH out of the tap is 7.3 and the PH in this tank is 8.2.

I hate being BSed to, the guy at the aquarium swore it would not increase or decrease the PH at all, he even showed me some that would increase it.

Now I have 40kg of 2mm black gravel I can't use and I'm back to square one. Any ideas on a dark/black substrate that is inert?

Dean, do you recall the name of the stuff you were using in your 4foot cherry tank?

[pappyy3]

What brand of black gravel did you buy?

I'm thinking that you may have been sold gravel that is commonly used for African Cichlid tanks - which has been designed to raise and buffer the PH ......

If you asked for inert gravel, and got something else, then take it back to the dealer and ask them to swap it over or give you your money back ;)

After all, you simply didn't get what you were after ....

[Trav80]

It was 2mm midnite black gravel. I will try get down to the aquarium this weekend. I figure they won't do anything, if that's the case I will not go in there again.