Want to use old LR for new tank

[O-Pee-Chee]

It's not a huge amount of rock and I've had it in my possession for 5 years now.. It's just rock is stupid expensive around here (~9 a lb) so it'll cost me about $200 to replace it. I don't need anything for the tank so the idea was it would be free and easy to get going.

I do worry about phosphate leaching tho. I had serious algae problems before but it was in a stock biocube with the bioballs and everything in the back so it was more likely caused by the nitrate factory in the back. I'm not using my biocube this time tho.

So, I guess the real question is, should I just buy new rock?