120 Community tank

[Theo1994]

Hello dear community,

I set up an 120 with 70 cardinal tetras, 50 nematobrycon palmeri, 15 hasemania nana, and 11 apistogramma agassizii, of which 5 are "wild" type, 5 are " fire red" and 1 is "Double red". My 1st question is if the different color types can breed. I know I wont have much of a chance for offspring, but thats another story.
On another issue, my plants came with extra snails. There are a lot of physa and ramshorn in my tank currently, but theres a helena as well, so I see some white (dead) shells every day, and I cant remove all of em. Because I run my tank with 80% RO water and 20% tap (300 tds, 7,5 or sth PH), and I want my PH to be nearly 7 or lower, is there any chance the shells will harden SUBSTANTIALLY the water?
Also, whats your opinion on AMTRA and OCEAN NUTRITION frozen foods (daphnia, artemia etc)? I hope I m not breaching any forum rules, but these 2 brands are the only available near me and as one is half the price of the other for the same product, I would like some feedback on quality etc.

Thanks in advance.

 

[Mike Wise]

Your agassizii will cross. Any survivors will probably appear more like wild aggies, which are polychromatic anyway.

Feed what your apistos are willing to eat.

As for the snail shells, I imagine the have little impact on hardness in such a large tank.

 

[Jon Webb]

Save those shells for those of us who like “shellies”!

 

[Theo1994]

I d be glad to give u those, if u ever visit Greece pm me!