Cardinal Tetras Dieing

**Basic** · 10-10-2012, 07:12 PM

I have a 30 gallon tank fishless cycled and fully stocked for approximately two months.

My stock is:

6 cardinal tetras
6 harlquin rasboras
3 bolivian rams
6 sterba cory cats

water params:
ammo: 0
nitrite: 0
nitrate: 10-40 (changed every 3 days ~30% to maintain nitrates under 40)
temp: 76
pH: 8.0

Everything was happy for approximately 2 months. Last week I lost a tetra. Since then I have lost 3 more. The dead ones have no signs of disease. Nothing has changed with my water conditions so I'm not really sure what to do. Any help would be appreciated!

**jeffs99dime** · 10-10-2012, 07:17 PM

Ph is way too high for everything in your tank, especially the rams and cardinals who are easily affected by high ph.
http://www.aquaticcommunity.com/fish...onaxelrodi.php
http://www.aquaticcommunity.com/fish/bolivianram.php
I'll be willing to bet that your water is very hard also if you ph is that high.

**Basic** · 10-10-2012, 08:03 PM

I had been told that the fish would be okay acclimating to this ph. Is there a reason that this would suddenly become a problem? Is it normal for the ph to take so long to effect the fish?

**Basic** · 10-10-2012, 08:24 PM

Originally Posted by jeffs99dime

Ph is way too high for everything in your tank, especially the rams and cardinals who are easily affected by high ph.
http://www.aquaticcommunity.com/fish...onaxelrodi.php
http://www.aquaticcommunity.com/fish/bolivianram.php
I'll be willing to bet that your water is very hard also if you ph is that high.

I just spoke to the local pet store, they are recommending a product to regulate the ph at 7, Neutral Regulator from Seachem. Is this the right thing to use? Is there another alternative?

**steeler1** · 10-10-2012, 08:47 PM

Chemicals are quick fix's but not that benificial. Buy some Organic peat moss and a filter bag and place in your filter, this will soften the water and bring down the PH.

**Lady Hobbs** · 10-10-2012, 10:16 PM

You can easily raise pH but you can not lower it. It will drops for an hour or so then shoot right back up again. pH is only supposed to be moved about .4 in any 24 hour period.

If you are planning on dropping the pH from 8 to 7, that is not 1 point but 100 points.......I believe.

**Cermet** · 10-10-2012, 11:55 PM

Nirates should be under 10 ppm for Cardinals! These fish need pure water (nitrates under 5 ppm better still) and higher temps than most common tropicals. Your temp is in the low range for Cardinals. Try 80 - 82 F and much lower nitrates and I would think they would do a lot better. I agree the pH is far too high (most Cardinals are wilds and these have pH's well under 7.0) but that is very difficult to fix unless you use some RO water. Chemicals are NEVER the answer since these are expensive and hard to maintain as well as control water pH.

**escamosa** · 10-11-2012, 06:23 AM

I would try raising the temp to 82 as well, and also keep the nitrates to at least below 20, before i try anything with pH. There's a fair chance that if you bought the tetras from a LFS in your town, that they would of been keeping them in the same tap water as you are. I could be wrong, but I have a feeling that it's water conditions, unrelated to the pH, that's causing the die off. If you're having to do a 30% water change every 3 days to keep the nitrates under 30, then you might be overfeeding, or maybe your filtration needs more maintenance or upgrading/additions.

How much and how often do you feed your fishes?
What do you feed them?
What filtration do you have?

**Dennis Bissett** · 10-11-2012, 10:01 AM

I'm guessing theyre not coping with the high nitrates - up your water changes to hold your level under 10

**VRB** · 10-25-2012, 10:28 AM

Probably not PH problem BUT....

If your water is high in PH 8.0 then your water is high in minerals, hard water. This can effect the cards and other fish. Don't bother trying to fix PH without first addressing hard water issues. This probably isn't the problem anyway.

Do you ever top off your tank from water evap?

Before you found them dead were they lively, freely swimming or hiding? Any signs of stress?

When you feed them are they actively eating or do they hide while other fish eat?

Hardness in the tank can build up if you top off from water evap, even with water changes. Let us know so we can all learn more about what's happened