Keeping Tetras and Other Soft Water Species: Please Help

[_Nemo_]

Hi,

I'm no guru in this hobby albeit my understanding of the basics. My interest
in the FW tank was stimulated mostly by the desire to keep small schooling
colorful species like the neon or cardinal tetras. Most of the species I'm
interested in seem to be soft water species.

Unfortunately, my tap water is somewhat hard with a pH in the vicinity of
8.2. My tank is 29G, and has 5 live plants and two pieces of Mopani wood.
Together with the dechlorinating conditioner I use, these factors seem to
soften my tap water down to a pH of about 7.5-7.8.

Eventually, I introduced 12 small neons to the tank. Within days, they got
ich and infected the three platys that were there for over a month.
Treatment with half dose methyl blue resulted in 50% loss in the neons (6
neons). The platys survived, including 2 fry that were in hiding. The ich
was still present after three (3) days of medication so I did a 50% water
change, added salt and raised the temperature. A week later the ich was gone
together with 4 more neons. In total I lost 10 neons to this outbreak.

At the time, I attributed the ich outbreak to chilling stress - or so I
reasoned/assumed. Back then I was making 25% daily water changes in an
attempt to control discoloration of the water by the recent addition of
Mopani wood. Since then, I've learnt to accept Mopani Tea, and to heat the
aged water prior to adding it to the tank.

A couple of weeks later when I thought conditions had stabilized, I
introduced 12 more small neons and 5 ghost shrimps. Unfortunately, the neons
started immediately dying off at a rate of one fish per day. Within a week I
was left with only 6 neons. The platys were fine and so were the ghost
shrimps.

This was most disturbing because all of the water quality parameters were
fine. Granted, the pH was slightly elevated for optimal neon conditions, and
I keep salt concentrations of 1 tablespoon per 5 gallons, but it was my
understanding that the neons should adapt to these conditions as long as the
water quality is good.

I tried different things to stop the fish loss. First I did a 25% water
change without adding salt to reduce salt concentration.. Then I was making
water changes every other day to keep the water quality high. Then I cleaned
the filter foam and vacuumed the gravel thoroughly to minimize suspended
solids. Finally, I changed the carbon filter to improve organic and color
filtration.

Changing the carbon filter was the trigger that marked the arrest of neon
loss. It has been 4 days now since my last casualty, but every time I look
at the tank, I can't help but count the little guys to make sure they're all
there. I am not sure the problem was the dissolved organics because I change
the carbon filter every 4 weeks anyway - when I replaced it, it was due for
changing!

I would like to continue keeping neons, and hopefully add more soft water
species in the future. To this end I feel adjusting the water chemistry in
the tank to optimize the conditions and minimize fish loss may be necessary.
This goes against what I read about matching the fish kept to the local tap
water chemistry and not the other way around. But, frankly, soft water fish
is what attracted me to the FW hobby in the 1st place - I would turn this
tank to a hospital for my SW aquarium otherwise.

Having said all of this, here are some questions. More may follow:

- Are neon tetra sensitive to dissolved organics? Do they have special
requirements with respect to changing the carbon filter more frequently?
- Is it necessary to lower the pH to 7.0?
- What is the safest way to soften the water in a planted tank?

Many thanks

 

[TankGirl]

Well, there is a lot to discuss here! (Welcome to Aquarium Advice, BTW)

The easiest way to lower pH in a planted tank, assuming your KH is above 4 or 5 is to use CO2. You can also use peat in the filter, but the CO2 will certainly help the plants, even in lower light conditions. However, the neon CAN thrive in your water. It may have something to do with how you acclimated them when you got them. If the water conditions at the LFS were different than yours, and they went right in the tank (or quarrantine tank, as the case may be, hint hint) then that might be the problem right there.

I am assuming you understand the nitrogen cycle and are testing the water for ammonia, nitrite and nitrate, and the first two are zero, and the third is kept below 40ppm, or even lower for those neons or cardinals (nitrates must be low with the water changes you are doing - I am a water changing fool as well ).

The use of carbon is debated often, and I personally do not use it unless I am trying to remove medication, so I do not know that this would make or break it for the neons in your situation.

I do not use salt in my planted tanks, as they are not a fan of it unless you are talking about java fern, which can tolerate it. I would discontinue the salt if you are abandoning the livebearer route, but there are a lot of folks who use salt regularly and swear by it. Matter of opinion, and again, debated often.

If you slowly acclimate them to your water parameters, including temperature, keep the nitrates low in an established, cycled tank, then you are doing all you can. If you want a lovely colorful fish that appreciates harder water, you could go with guppies or Endler's livebearers, but I think you can keep neons, as you obviously are willing to make the effort to create the proper conditions for them.

 

[Allivymar]

Hiya nemo and welcome to Aquariumadvice.

I think your problem is not so much your water as it is the domesticated neon species themselves. If you do a search about them here, you'll find many of us have had very poor track records with these guys, despite good water husbandry, quarantine procedures and experience.

We think its due more to the inbreeding of neons then anything else at the oversea fish farms. And apparently the stock on the eastern side of the Americas is not as hardy as the stock on the west coast.

Other things to consider is salt seems to be a no-no for tetras; they don't appear to do well with it. Quarantine is imperative for these guys as they usually are carrying some sort of disease, either ich or neon tetra disease.

I currently have 4 neon/cardinals in my tank out of an original amount of 11 (not all bought at the same time, and some never made it out of QT alive). I do nothing special for them except make sure they are well fed, and do small water changes once a week (its a well planted tank). This lil bunch seems to be healthy enough, and have been in the tank since August.

 

[Orca]

I also had similar questions as NEMO concerning Neons and soft water. I just set up a 6 gallon tank with 6 neons. Like NEMO, my tap water PH is also quite high at around 8.6. Prior to getting my fish, I tried unsuccessfully to lower the PH using Seachem Liquid Neutralizer. Even after using quadruple the doseagel, the PH didn't budge. I eventually got the PH down to 7.0-7.1 using some Wardley's PH Down, so that's what I used in my tank. The neons seem fine so far - only had them a week though.

Is using a chemical to lower the PH a bad thing? How exactly do you put CO2 into a tank?

The water in the LFS where I bought the neons was PH 7.6. Was it a mistake for me to put the neons into a lower PH environment just because they usually prefer that?

Thanks.

 

[BrianNY]

I'll go on the record with TankGirl and Alli here. IMO there are certain probs with the stock of neons and cardinals made available to us. Although I'm not entirely sure what exactly it is. I just know that deaths seem to be far more frequent than other tetras. I finally gave up in frustration with cardinals and opted for rummy nose tetras and rasboras.

I'm no fan of PH buffers. I think they can cause violent swings in the PH which is much more stressful to a fish then acclimating itself to your water. Now that I've said that there is a product called chemipure which I used to use. It was very good at stabilizing the PH to 6.8. It's carbon (sheesh I don't believe I said that), but as long as you're willing to change it every month, I think you'll be fine. One more thing, if you use it limit the water change to no more than 20% at a time.

 

[stoneydee]

And I wouldn't worry too much about the tannins from the wood - neons actually prefer black water.

 

[tabitha]

neons are so pretty but i have NEVER had luck with keeping them.. usually after about a month they all die!! they are sooooooooo sensitive...

good luck with keeping them.. you will need it!! but you will enjoy it in the long run im sure

 

[bobolink]

I have had good luck with neon tetras but the secret is in acclimating them to their new home.
When I get them home I float the bag and add 2-4 tablespoons of water -from their new tank- every 5-15 minutes until I've doubled the water volume in the bag. This might take 4 to 8 hours. I then net the fish into their new tank. I've heard of other people rigging and siphon hose with a valve that allows 2 drips per minute into the bag. I'm not that anal and neither are my fish
I've also just dumped the bag of water and fish into the tank but not if I had expensive fish in there already.
Also. only add neons to a mature (cycled) tank. They do not handle ammonia, nitrate, nitrite spikes very well.
I have had 6 neons in an eclipse 6 on my desk at work for 18 months with no problems.
I also helped a friend with a 90 gallon planted tank that had two goldfish in it. We removed the goldfish and thinned the plants and added 40 neon tetras as described above. They have been in there for 6 months with only one loss. That fish died about two months ago.
With proper acclimation neon tetras are not as delicate as their reputation.

 

[Terry]

I agree with Tankgirl, Alli, and brian on this one.

But i would like to say that here in the UK we don't seem to be getting the same prob's with neons and cardinals as you guys in the States.
There is another thing to look at when it comes to Neon Tetra and Cardinal Tetra, it is not just the colour differance that make these fish differant. Yes they do both come from the amazon but the amazon is a vast area. In all the years i have been keeping fish the neon and the cardinal have always been seperated by differant water ph. The neon Tetra comes from the more northern part of the amazon and the cardinal Tetra comes from a more southern part of the amazon. I am not saying that would make a differance i just think that when you look at the differance between the two fish that there might just be something in where they come from. I have noticed that when people buy Cardinals in the UK that they are treating them differant as in the fact that they are putting them in with Discus etc. at a lower ph and a higher temp. When they buy there neons they are putting them in there general community aquarium with a slightly higher ph. The other thing to look at as well is that alot of the fish you buy now are breed thousends of miles away from the amazon and the ones that you buy in your lfs have probably never seen the amazon.
I have to finish off by saying that if you get your water parameters right in your aquarium and the fish are still dieing then it must be something else. It must be a very stressful life being a captive Tropical fish, you spend time being shipped around from piller to post in bags which must be very stressful, but hopefully you end up in an aquarium of somebody that will care for you.

 

[TankGirl]

The water in the LFS where I bought the neons was PH 7.6. Was it a mistake for me to put the neons into a lower PH environment just because they usually prefer that?

Not at all! It is certainly a desirable thing to try and create conditions that will help fish thrive, but I think often the fish we get at the LFS are tank raised for many generations and have adapted to the local conditions, and it is often more harmful to try to manipulate water conditions. This can create pH swings, which causes the fish to die, and then the fishkeeper thinks there is a problem with the fish, rather than with the water chemistry. When you manipulate pH you have to consider your KH or you will have problems, and some very regular testing of water parameters needs to be done so you can see what is going on. It is not something for the beginner to fishkeeping.

 

[ScottS]

Hi,


Unfortunately, my tap water is somewhat hard with a pH in the vicinity of
8.2. My tank is 29G, and has 5 live plants and two pieces of Mopani wood.
Together with the dechlorinating conditioner I use, these factors seem to
soften my tap water down to a pH of about 7.5-7.8.

Just in case, there's a difference in softening your tap, and bringing down the pH. I think the bigger concern for tetras is the hardness more than the pH. Your tetras will do fine in that 7.5-7.8 pH range, just try and keep it consistent. I think the hardness is the bigger factor. My tap is similar to yours, near 8 pH and about 26 GH. When I do water changes, I use reverse osmosis water I buy at the grocery store ($0.39/gallon) with my tap water in a 3:1 ratio that gets me down to around 6 GH. The pH also decreases with it, but I don't even worry about that. I check it occasionally, but just concentrate on changing water at similar ratios. I'm keeping a dozen Cardinals in that water.

 

[TankGirl]

That is a very good point, and the stability of pH is controlled by the carbonate hardness, or KH (alkalinity). You could have higher pH water and still a low KH, so it is very good to know these values, as well as GH.

 

[_Nemo_]

Thanks a lot for all the feedback I got (and for the warm welcome ).

The surface water courses used for water supply in our neck of the woods are generally acidic, and since acidic water causes corrosion in the water supply lines, I believe/guess/assume that the public water utility raises the alkalinity of the water and buffers it to keep slightly alkaline ( >8 ) conditions in order to minimize corrosion. This is the pH I measure for my tap water.

I am guessing that the combined effects of adding the dechlorinating conditioner, the Mopani wood leaching, and plant photosynthesis is causing a reduction in the pH to the 7.5-7.8. For this change to happen in the 1st place, the buffers in the water must be overcome! What this means is that just knowing there is a difference between tank pH and tap water pH is a pretty good indication that the buffering capacity of the tank water is low.

I have not measured the Alkalinity and Hardness of the tank and tap water yet, mostly because I don’t remember the relationship between them and the pH anymore and don’t know what to do with the information. No excuse though! I shall pick up a test kit this weekend and dig up my old CHEM 101 notes. However, I believe the assertion made above is still valid: The buffering capacity of the tank water must be low.

Ok, then. If this is the case, will I be making things worst by adding agents that lower the pH? I don’t think so. If there are no buffers in the water anyway, the pH is already unstable. In fact, I would be doing the fishes a favour by adjusting the pH - slowly - to their evolutionary liking, and then buffer it at that level.

Am I making sense, or am I simply lying to myself based on some unsubstantiated assumptions?

I understand I should stop adding salt to the tank if I want to go the soft water route. This is most unfortunate because, I find, the salt bring the fishs’ best colouration. But I did see some deterioration in the general well being of the plants since I started using it.

I use a hang on filter at this stage (AquaClear 300). As such, using peat in the filter is not currently an option. What I can do, however, is add the peat to the water-change water while it is aging. It wiould be interesting to see what colour water I will get then, considering that I already get quite a bit of discolouration from the Mopani in the tank .

As for adding a CO2 reactor, I am not sure I have the room necessary. My FW tank is only 29G and it has no sump. If I can find something that fits, I will certainly consider using it.

As for carbon filtration, I find that it generally enhances the odour and colour of the water, and that alone makes it worthwhile for me. I understand that some of the activated carbon being sold leaches phosphates, but I haven’t had any problem with algae yet (touch wood).

I will be using the acclamation methods suggested in this thread. This is something I haven’t been doing. It must be quite the art floating the bag in the tank while slowly adding small quantities of the tank water to it. I’ll have to learn the proper procedures I guess.

Incidentally, all six neons are still alive and kicking (day 5) and they seem to be in good health now. In fact, I went home last night to find one of the adult platys infected with ich and I moved her to a hospital setup. But the neons and other platys seemed unaffected.

Many thanks again

 

[_Nemo_]

I posted my message before reading Scott's reply. I was not aware that tetras are more sensitive to hardness values. Thanks for the input.

I will have the kH and gH of both the tank and tap water tested by the end of the week. Luckily, I already have an RO/IO filter which I picked up a few months ago for my SW setup.

 

[TankGirl]

I would be interested to know the pH of your water right out of the tap, versus about 24 hours after sitting. I will bet you it is lower, and you have the right idea about the buffering capacity. If that is low, then your chemical manipulations are going to cause swings, plain and simple.

You can get a Hagen CO2 system that consists of a canister that you can either suction-cup to the back of your tank or can sit on the floor, with an air-line tube going into your tank and a ladder-type diffuser that is relatively small and low-profile and should fit in your tank.

Here is an interesting, basic article about pH and hardness. http://www.drhelm.com/aquarium/chemistry.html

 

[_Nemo_]

Thanks TG. Much appreciated.

 

[shawmutt]

Whew...first of all, sorry if I'm repeating what someone already said...that was a lot of reading!

I've kept cardinals for about 8 months, they would have lived a lot longer but stupid me introduced ich by added unquarrantined fish, hatchetfish to be exact. The ich killed all but one, which lived another 2 or 3 months before my smaller tank sprung a leak and I had to give him back. Here's a few things I did, but may not work for all--they are just my experiences with cardinal tetras.

1. I had the school of 9 in a 30 gallon tank, with some other fish. I believe these fish aren't really meant for anything smaller. One reason is that when these fish are alarmed they emit a chemical which draws them closer together, and they remain this way (stressed) until the chemical dissipates. In a small tank, they are more likely to get scared more often, and the stress will likely kill them quicker.

Another reason is that the bigger tank gives some leeway if a mistake is made in the water quality. Water stability=less stress.

2. I had many many hiding places for them. So many in fact, that I could sit in front of the tank and not see any of them. I had to sit really still in front of the tank for a good 5 minutes before they would venture out and resume their normal activities. If I moved a finger, they would dart back into hiding and I'd have to wait again. This was also to reduce stress.

3. Everything was quiet and dark. I set up a black water biotope (check my gallery). The back and sides of the tank was covered with black background. The gravel was black. I added blackwater extract to tint the water. It looks murky, but they cardinals really seem to glow in such a setup. There were no airstones, the hose and air bubbles are from a DIY CO2 system I was trying. I had a big piece of driftwood in there to help soften the water and for more hiding.

4. And the most important thing--IME, of course. I used distilled water and store bought r/o water. I used this stuff called Electroright to add trace elements. It had the additional benefit of automatically setting the water hardness and pH to very low levels. I still use the water it in my current tank (Lake Malawi Biotope) but use salts and Proper pH 8.2 instead of the Electroright, because the pH and hardness is quite different. But I really will swear by the r/o water, my tap water is junk and I was losing fish until I switched.

Basically, it seems I had luck with these fish by using high quality water and setting up an environment that was as stress-less as possible. HTH!

 

[Madame_X]

I second that. Its a lot of work to change your water parameters and most importantly keep them stable.

I've gone to great lengths to lower the PH and general hardness of my tapwater to try and provide a more suitable home for my Bolivian Rams. Since I didn't want to use chemicals (not stable enough), I opted to mix half R/O water with my tapwater. This has little impact on the PH since PH is exponential, but it does lower the KH substantially. I then add CO2 to bring the PH down to 7.0. I test it at least once or twice a week (usually more).

This would all be fine if I had an R/O system at home, but instead I have to trek down to the local Water 'n Ice store to fill up my 5 gallon jug every time I want to do a water change. Not always convenient!

 

[TankGirl]

Whew...first of all, sorry if I'm repeating what someone already said...that was a lot of reading!

Yes, this is turning into quite a thread! Shawmutt, I am reminded of when I had my cardinals in quarrantine in a 10-gal. There were about 8 of them and they basically hid all of the time, until I put them into the 55, when they would school beautifully and caper in the filter outflow. One day I lost all of them but one, don't know why, but that one is still going strong all by his lonesome, trying to hang with the white clouds!

 

[_Nemo_]

As it turns out, I have very soft tap water with high pH

Tap Water:
pH: 8.0
kH: 3
gH: 3

Tank Water:
pH: 7.8
kH: 3
gH: 4

So it seems that all is needed in this case is to slowly bring the pH down to 6.8-7.0 and buffer it there.

CO2 addition and peat filtering will be done in the future in conjuction with the transforming the tank into a true "Planted Tank" (new substrate, drilling the tank, etc.) However, this may take some time to setup. In the meanwhile, I could adjust the pH using a phosphate free chemical such as Seachem 'Acid Buffer". What I would be more interested in, however, is the potential use of citric acid (lemon juice or crystals).

I don’t recall reading anything about the use of citric acid in FW aquaria, and presume there must be good reasons for it. I can’t help but think, however, that citric acid is a an excellent candidate for pH adjustment in aquaria.

Citric acid is a phosphate free naturally occurring fruit acid, It is THE most widely used organic acidulant and pH-control agent in foods, beverages, and pharmaceuticals. Citric acid crystals are non-toxic, odourless, biodegradable, and freely soluble in water. To top it all off, the decomposition of citric acid in solution produces free CO2 !!!

I’m I dreaming or what?!