What went wrong?

[DutchTulips]

Hi everybody,
Apparently I've posted my posts/question on a wrong page AGAIN, so I'll start again here and hope it‘s the right place. (Can anyone tell me where to go??).
I'm from the Netherlands, but moved to the USA in 1992. Have traveled a lot and now am finally in a place to stay. I'm all excited that I'm finally able to have an aquarium again.
We bought a small aquarium, 10 gallons, while looking for the best way to have a big aquarium again. Bought a 70 gallon tank and my SO built the cabinet around it, so it's custom fit for the wet/dry filter.
In the meanwhile we found out that our wellwater was too alkaline. Tried tablets and fluids. It lowered the pH, but only for a day. In Holland I used to filter over peat to lower it, but haven't found peat here. It would become very costly to use that fluid every day in a 70 gallon tank, so we tried something different.
We bought a Reverse Osmosis filter. Great pH, but it only puts out a few gallons a day. To fill the big tank faster, we bought distilled water in gallon jugs and thought that after that the RO system could keep up to refill.
We put plants in and ,after a week, a few cheap fish to see how things would go. pH was ok. A couple of fish died, but the others seemed ok. Got some more fish, but then noticed that pH went out of wack again! What happened? I know plants can make it go up, but the fish should make it go down again, right? Or wrong?
How come it changed so quick and what can I do? Fish are dying :(
Is the water maybe too "sterile"? Nitrite level is zero.
Any good advice?

[themusician]

At this point your most important measurement will actually be ammonia, not nitrite (ammonia comes first in the cycle and you probably haven't had fish in there long enough to get nitrite). What is your ammonia reading?

Also, what is your pH reading? Depending on what fish you are going to keep, almost all tap and well water is in an acceptable pH range. Your fish may have died from the instability in your pH. Unless your pH is higher than 8, you should probably be okay just leaving it as is.

[Rue]

You can buy peat...just buy it from the Garden Stores...

R/O water is fine for top up for an established FW tank, but is too pure (as in lacking in minerals) to use exclusively. SW tanks are different, since we want pure water to add the salt mixture too...which has all the necessary additives in it.

We also have well water and while it's fine for fish, it's too yellow (blackwater) because of our high tannin content...I don't like using it.

So my hubby has been bringing 'city water' home for me for my FW tanks (total of 97 g) and I use that instead. It's not that big of a deal actually...

[DutchTulips]

Thank you so much...I just tested the ammonia level and the result seems somewhere between 0.50 and 1.0
The pH is 7.0
Where do I go from here?

[Rue]

At those levels you haven't really cycled yet, so since you already have plants and fish, I'd just keep up with water changes and monitor your levels until your reading stabilize...then you can get more fish.

Try hauling city water...we've been doing it for 11 years now...it's just become part of the weekly routine...

BTW...we also have an R/O system...great drinking water for us! Coffee and tea tastes so much better!:18:

[msjinkzd]

A large water change to reduce the ammonia reading, ideally as low as you can get it.
You could also try mixing the RO water with your well water for water changes.
You are probably going to have to do daily large water changes while cycling, it may be best to just give your well water a shot. I use my well water which has a ph of 8 and my fish are thriving (my sterbais spawned last night, my gouramis earlier this week, and my cherry shrimp are multiplying like its going out of style). Hope this helps, good luck.

[DutchTulips]

My wellwater reads 0 on ammonia level and 7.8 on pH.
My tank is 70 gallons. How much should I replace each day and also, would a mixture of wellwater and R.O. water work best?

[DutchTulips]

I replaced almost a third of the water with a combination of wellwater and RO water. Ammonia level is now 0.25 and pH is 7.4
Will do the same tomorrow and hope for the best. Thank you for your advice!

[DutchTulips]

Have been doing water changes with a combination of wellwater and RO water, about a third every time. I added Cycle liquid to my (planted) aquarium. Ammonia levels have dropped to 0...Nitrite and Nitrate went up to 0.25 and 5.0

I haven't changed the water since the day before yesterday. I checked the levels this morning: Ammonia is 0; Nitrate is 0.25; Nitrate is 2.5; pH 7.4
No fish have died since day before yesterday. Should I do more water changes?