Uaru breeding project and a few questions

[Beetlebug515]

Hello all. I have been wanting to breed uaru for a while now, and after a request at my LFS I came home with six juveniles today. I have two older uaru as well bringing my total to eight. The eight are going to have their own 75 gallon tank, and I was curious what water conditions you guys have had success with. How picky are they? My tap water measuers 8 ph, 9dkh and 18dgh. I don't really want to mess with it if I don't have to. I was considering using peat in the uaru tank if need be though.

Other question: while I was taking the hardness tests on my tap water, I decided to measure my 250. It came back as follows:
PH-7.4
KH-22
GH-20.

???????
I have several large pieces of driftwood that I didn't soak because I wanted to lower the ph a bit, but why is my tank water so much harder? My only suspects are the substrate and bio media. Substrate is black diamond blasting sand and bio is seachem matrix, bio balls, and lava rocks. I have never had this substrate adjust my hardness before, but ive also never had the lava rocks or matrix change it either. At least not that ive noticed. Have you guys had these materials alter your chemistry like this? Thanks in advance!!

 

[Beetlebug515]

Got the uaru in a bare 60. I think this will be their home for a while.

 

[axs377]

Great looking little guys. Is your plan to grow them out a little and put them in the 250? Or are you cutting back to 1 pair in the 75? A ph of 8 may be a tad high to expect them to breed. It is a tad high period for them, however I also am not a huge fan of messing with water parameters. I'd grow them some first and then worry about the water. What about an ro/di unit?

 

[Beetlebug515]

I want to keep whatever pair I end up with in a breeder tank ideally. There be monsters in the 250, so the pair won't be going in there. I have considered an ro unit, but from what I see online I will end up having to store a bunch of water all the time. I mean, 50gpd, 100gpd, etc. Sounds like it would take forever to do a water change unless I stored it. Unfortunately, I just don't have the space for water drums.

 

[axs377]

I have a 40gpd drip setup on my tank, something like that might not be a bad idea. Aside from that I'd probably play it by ear. Let them grow and pair up, if they don't breed then work on water parameters in lowering the ph.

 

[Beetlebug515]

What size should they start pairing up? Would you happen to know what the breeding age is?

 

[Beetlebug515]

I think I may have figured out the hardness issue. I recently added a couple of pothos to consume nitrates. The soil they came in had fertiliser in it. The fertiliser looked like little pumice stones and I tried to get them all out of the roots, but if I missed some I think it may have dissolved into my water. I know that calcium is a micro nutrient used in many ferts. Calcium in ferts dissolved into calcium carbonate resulting in high Kh? Maybe?