# Low pH, high nitrates, compatibility/# of fish question



## tfish77 (Apr 29, 2009)

Hello, and thank you in advance for any advice you can offer me. I've been keeping fish for a while, but I still feel like a beginner because I don't do to much with my tank other than feed the fish, watch the fish, and change the water/clean the filters. So I won't be offended if anyone talks to me like a beginner - I'll be grateful!

*Background*
I have a 50 gallon "tall" freshwater tank. It was given to me by a friend with some fish in it 2 years ago (I'm down to 3 of the original 9 fish), and is the 2nd or 3d tank I've ever owned. The tank has a Fluval 4 filter (normal pads) and I often add an Algone packet between the pads as well. It has plastic plants, a large piece of driftwood, a few oddly-shaped rocks (suitable for hiding under) and gravel substrate (more like large pebbles).

I have a submersed heater and I keep the tank temperature around 78F.

I usually do a 20-25% water change (including vacuuming the gravel) every 2 weeks or so. When I add new water, I add API Stress Coat to treat the water, and usually nothing else.

*Recent Developments*
I recently moved apartments, and despite living through 2 previous moves, this one was apparently very stressful on the fish, as I lost several in the days after the move. I recently (around a month ago) added some new fish, and I've lost a couple from that batch as well - 2 of the new fish were redtail sharks, and they died after a few weeks of being added to the tank. One died of a fungus infection (I treated the water with an API anti-fungal and everyone else seems to be OK) and the other died of reasons unknown a couple weeks later. I'd really like to nail down what's going on so I can keep a healthy tank!

The current occupants are:
-2 large black skirt tetras
-1 Featherfin Catfish
-2 Banded Leporinus
-2 Kissing Gouramis
-3 Black Neon Tetras (tiny)

*Questions*
I have a few questions that I would really love some help with:

1) My pH (as measured by an API liquid kit) is at 6.0, and has been for a few months (since I started testing). I tried pH Up but have since read that it doesn't really do much - and I'm afraid of causing a large swing in the pH and making things worse. I've heard advice such as "add a mesh bag full of crushed coral," but I don't know if that's a good idea. I'm going to be doing daily water changes (~20%) for the next week to see if that helps, but...why is it so low? My tap water measures at around 6.6. I'm trying to avoid falling into the trap of just adding things to my water and potentially causing huge changes all at once, but I'd like to understand the root causes here and address them if possible.

2) My nitrate level has been in the 40-80 range, which I know is high. The Algone is supposed to help with this, I know - but it's been there for a couple weeks now. Again, I'm hoping the week of daily water changes will help this, but I'm not sure why it's happening. I think I may have been over-feeding for a while, but I've since scaled back (a few shakes of the flakes every other day, an algae wafer or two every few feedings). (For what it's worth, my ammonia level has been around .25).

3) I've been told that my tank is big enough to support more fish. But I don't want to do add anybody until I have these parameters stable. And of course I want to keep compatible fish. I would love to add the following, is this a good idea? (once I have the chemistry stabilized):
-2 redtail sharks (I really liked having those guys in there)
-6 black neon tetras
-2 Boesemani rainbows
Is that too many total fish? Would they play nice together? I know a few (redtails, leporinus) are "semi-agressive," but they seemed to get along OK before (before the redtails passed away).

What do you think? Thank you all in advance for reading and for any advice you can give me.


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## Betta man (Mar 25, 2011)

Are you treating your tank with other chemicals? The nitrate problem might be from your tap, but that isn't likely. I have corral in my tank and my bettas are happy with it and I have no problem with water parameters, so it might not be so bad. Try adding a little at a time.


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## phlyergirl (Nov 6, 2011)

The nitrate issue is because you are doing such small water changes so infrequently. Bump it up to 30-40% a week. Or more. 

I'm not a fan of using chemicals to alter pH. I'd rather have a stable pH than an ideal number. Larger more frequent water changes will help that too. It won't have time to crash.


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## tfish77 (Apr 29, 2009)

Thanks for the replies! No, I'm not using anything else to treat my water. I'd been told that changing more than 25% at a time (on a regular basis) can be detrimental to the fish, is that true?


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## emc7 (Jul 23, 2005)

The first water change with new water should be no more than 25%, but you can increase the percentage for the next one and the next one. Changing 25% will take nitrate of 40ppm down to 30 and it will be back up in a week. To get it down more, you need to either change more or have a plant or algae eat it (or use an ion exchange like nitrasorb). I'd be inclined to do 25%, 50, 75, & 90% water changes on subsequent days. Changing a lot of water with new water that is different in pH, kH or temp is bad for fish. But once fish are in water very like your tap, changing a lot of water is not that bad. Starting small will give you a chance to observe any ill effect from the water change. Watch as you add and if fish act stressed, slow down and take a break before you continue filling. Once you get your nitrates very low (say about 10) you can figure out what water change amount and frequency you need to keep it down.

Nitrate could have just crept up over time as your increased feeding wasn't matched by increased water changes or it could have got a bump from dead fish or dead algae. In any case, it is easier to keep it down than to get it back down. 

I like bosemani rainbows, but they are big and swim fasts and like to be in large groups. Unless you tank is 48" long, I'd rethink these. With your low pH, smaller turquoise or threadfin rainbows might be better anyway. 

Nitrate is acidic, so fix this first before you worry about pH. Then have a store test your tap water's gH and kH or TDS. Low numbers mean low "buffering ability" and pH will tend to drift down. The bag of crushed coral recommended will slowly up kH and should keep the pH from free-fall.

I'd guess that your new water is significantly different than what you had before and what the store keeps fish in. 

Whenever you add new fish without QT, you risk both old and new fish getting disease and dying.


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## tfish77 (Apr 29, 2009)

Thanks for all the info! Very helpful. I'll try the 25%, 50%, etc. routine this week and see how it goes. Sounds like fixing my nitrate issues might well address my pH issues as well, but I'll have the store do those tests too so I know what my tap water is capable of buffering.

Thanks also for the advice about the rainbows - my tank is 48"(W)x21"(H)x12"(D) so it sounds like it's big enough. I didn't realize they liked to be in large groups, though - not sure how many I should put in there.


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## phlyergirl (Nov 6, 2011)

tfish77 said:


> Thanks for the replies! No, I'm not using anything else to treat my water. I'd been told that changing more than 25% at a time (on a regular basis) can be detrimental to the fish, is that true?


No, not true, as long as the pH and temp is not hugely different. I regularly do 90% changes. I'm not sure why this myth persists. Discus are thought to be super sensitive fish, but ask how many discus keepers do below 20% water changes.


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## lohachata (Jan 27, 2006)

ok...i am going to stick my big nose in here for a minute and may possibly step on a couple of toes.....
it has been my experience............................................
Leporinus Fasciatus will grow to well over 12" and is a very aggressive fish...
Helostoma Temminkii will grow to 12" or more and can also be very aggressive... 
Epalzeorhynchos Bicolor can exceed 8" and can be fairly aggressive...
none of the above species should ever be considered "community" fish...
they are also not really suited to a 55 gallon tank....it is ok when they are young ; but would soon need a much larger tank..

personally i think most of your losses were the result of attacks from the leporinus and/or kissing gouramies....

i agree with doing the progressive water changes...yes...that old thing about any more than 25% is hogwash...some discus breeders will do 100% daily water changes on fry for more rapid growth..same with breeders of many other species....

i also do not like using chemicals to alter water parameters...

unless the water comes out of your tap at a PH of 4.0 ; there is no reason on this earth to add coral to the water where a Betta Splendens resides....
tetras do not mind a lower PH such as 6.0.....it is often lower than that where they come from...keeping in mind that the leporinus is a tetra......

i don't know how long ago it was that you moved ; but if it was within the last 2 or 3 months and you tore down and reset up the tank it will be in the cycling process...
do not add any more fish until you get your system stabilized and are sure that it has completely cycled...then add only a few at a time...i would also suggest you set up a 10 or 15 gallon hospital/quarantine tank for new arrivals.....as was said bewfore...why risk killing everything...

good luck..i hope everything works out ok for you..


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## emc7 (Jul 23, 2005)

Good points. black skirt can get nippy, esp. in small numbers, Catfish can be predatory and the kisser's are one of the meanest things I've had and I keep cichlids. Unless you see a bigger tank in your near future, you need to plan for full size fish. I didn't comment on the other fish because I don't know them. 

If you mean the Fluval 4 260 gph internal filter. IMO, its a little light for a 55, I'd add another filter. 

Stubbornly high nitrates (that bounce back after a huge water change brings them down) could be caused by a cruddy filter or substrate, but go light on cleaning if you think you are "cycling". Having any measurable ammonia or nitrite would indicate this. A "mini-cycle" is not uncommon after a power outage, a move, or adding new fish. It shouldn't last long.

Aside from being disease vectors, the main issues black neons cause is violating the "mouth size rule". If they fit, they are lunch (or dinner, or midnight snack). If you put them in with fish that get big, they may get eaten later rather than sooner, but it will happen.

If kH and dH or gH #'s come back low, you should consider choosing all your fish from south america. Choosing fish that suit your water is easier than altering water chemistry. Even if you alter your water, its best to put fish that prefer the same water in the same tank.


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## TheOldSalt (Jan 28, 2005)

Nitrification lowers the pH, so if NO3 is high, pH will be low.


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## tfish77 (Apr 29, 2009)

Thanks all for the info and the help! FWIW, the skirt tetras are some of the original occupants of the tank and they barely ever seem to notice anyone but themselves. The leporinus (replacements for 2 that were in the tank) can get a bit nippy, but mostly one of them tortures the other one (same dynamic played out with the previous 2). The gouramis tend to spend their time eating algae off of the driftwood & plastic plants, and when they do fight, it's always with each other. As for the catfish, he's the oldest one in there and acts kind of like an old dog - he naps all day, nestled into the side of the driftwood, and occasionally comes out to surf the bottom for food.

All of which is to say that I suppose all fish are unique, but it's very helpful to have guidelines so I don't inadvertently cause a stressful environment, or one in which everyone's going to eat everyone else.

I'm going to stick with the larger water changes for a while and assume that this is a "mini-cycle" period which will hopefully settle down after a bit.


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## emc7 (Jul 23, 2005)

Keep an eye on nitrate, its the best way to tell if you are changing enough water. Have a plan for when aggression or size issues occur and watch your fish. All sorts of young fish are fine together until suddenly they aren't.


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