# Urgent! Problems with my NPT-what should I do?



## The Naturalist (Jan 3, 2007)

I am new to NPTs and have a 40 gallon aquarium that I posted about sometime ago that is now having fish dying. My aquarium has hornwort, cryptocorynes, Java moss, and a couple of small, sickly-looking Amazon swords. Because my aquarium is two years old and the gravel has a fair amount of mulm in it I did not add soil when converting it to an NPT. It has been almost two months since the last water change. All the plants except the Amazon swords are growing better than I have ever seen them grow. Unfortunately, the same cannot be said about my fish. I have already lost a few mollies and a guppy. I do not want to lose more. Do I not have enough fast growing plants? If so, what are some good, fast-growing plants for an aquarium that is only lit by two regular flourescent bulbs? In the short term, should I do a water change. I have a fluval 204 with a sponge as part of the media. I remember reading in Ecology of the Planted Aquarium that the bacteria on fine filter media could compete too much with plants in taking up ammonia. Could this be the problem? Should I remove the filter sponge?

Please respond quickly! I do not want to lose any more fish.


----------



## sb483 (May 29, 2006)

Emergent/floating plants are the quick growers - duckweed or water lettuce if you can find it. Mollies and guppies are hard-water; do you have soft tapwater? If so, harden it (eg. add dolomite to the filter & gravel).


----------



## The Naturalist (Jan 3, 2007)

I do not have a test kit for hardness; however, I have kept mollies in the tank for two years and they have not shown any problems until now. The guppies are relatively new to the tank, but I surmised that since mollies did well, guppies would also.

I have never seen water lettuce or duckweed at my local aquarium stores. I will look again, but are what are some other plants that might help?

In the meanwhile, should I do a water change? Or would that just make matters worse by removing plant nutrients?


----------



## littleguy (Jan 6, 2005)

It's hard to diagnose the problem without much info. Could you tell us your water parameters?

Ammonia?
NitrIte?
pH (compared to before)?
Nitrate?

Are fish gasping at the surface?
Are there any noticeable smells coming from the tank?

I have a hunch about what the problem is but just want to make sure it's not something else.


----------



## The Naturalist (Jan 3, 2007)

It has been a while (probably about 3 months) since I last tested, but when I tested the water today, all seemed normal and okay except for the pH. I have often heard of the pH in an aquarium steadily decreasing over time due to water problems, but I have never heard of pH rising on its own, especially the amount that it did in my tank.

Here are the paremeters:

Ammonia: < 0.25 ppm
Nitrite: 0 ppm
Nitrate: ~20 ppm (the lowest it has been in a year!:-D )
pH: 8.0 (Last time I tested, pH was about 7.2)

There are no bad smells and the fish are not gasping on the surface.

Could the pH change have caused the fish deaths? I know a pH change can be stressful on fish, but I didn't think that it would kill fish that actually prefer alkaline water. I kind of doubt that the pH is the problem, unless it is caused by something else that is fouling the water.


----------



## littleguy (Jan 6, 2005)

Ammonia is much more toxic at high pH. See here Ammonia Toxicity. Even though your ammonia reading is not extremely high, it can certainly be lethal at your high pH and over the course of weeks as you stated.

I would do a major water change and add some more fast growing plants. The hornwort is good, but the rest that you have are slow growers. You could add floaters like water lettuce or duckweed. Watersprite (ceratopteris thalictroides) also does a good job sucking up nutrients, and can be grown floating or planted in the substrate.

It concerns me that your sword is not growing well. This may be due to lack of a nutritious substrate. Long term I would worry about anaerobic conditions in a pure gravel substrate without healthy rooted plant growth. The mulm may help somewhat, but is not really a great substitute for soil in a low tech tank.


----------



## The Naturalist (Jan 3, 2007)

I don't know what constitutes "good root growth," but most of the bottom of the tank appears to have crypt and sword roots in it when I look underneath the tank. In addition, the cryptocorynes, which are also heavy root feeders, seem to be doing much better than they have in the past. Would adding a fast-growing rooted plant such as vallis help prevent anaerobic conditions if this is not enough?

Thanks for the advice; I will try to add in a lot more fast-growing plants.


----------



## littleguy (Jan 6, 2005)

Well if your crypts are doing well, then things should be just fine. I forgot you had them in there.

It's nice that you can see your tank from below - not all of us can do that with our setups. That alleviates my concerns about the substrate going anaerobic. If you see lots of white roots, then the substrate's healthy. If you see black roots, that means they're rotting. If you see big patches of substrate without roots, that *might* indicate something is amiss in those areas of the substrate. So you can do that simple checkup if you're ever worried about substrate health.


----------



## The Naturalist (Jan 3, 2007)

I'm starting to lose fish again, and am having a lot of algae. I actually don't mind the hair algae that's been starting to become prevalent, but am concerned that it might indicate that something is amiss. In addition, the water sprite that I put in after I first had trouble is slowly dying. At first I saw a couple of fiddleheads not long after I got them, but those were eaten by snails, and I haven't seen any more. All the other plants, even the swordplant, are at the best that I have seen them in a long time.

For a while, the fish seemed okay; I think the rapidly growing hornwort took care of the ammonia problem, at least for the time. Now I have just lost 2 guppies and 4 mollies. What could be going wrong? I tested the water and found trace amounts of ammonia. Why do I have ammonia in an established tank? Is it possible that there is something else in addition that is causing trouble?


----------



## JERP (Feb 4, 2003)

I don't think I'd recommend a brackish fish (molly) for a freshwater tank. The plants may very well have killed the mollies by growing too fast and absorbing all the salts. Mollies are very fragile in a straight freshwater tank. I've had better luck with them in a pure saltwater tank.

How much, how often, and what do you feed your fish?


----------



## mistergreen (Mar 3, 2007)

Yeah, Jerp is right. Guppies & mollies need some salt in the water to stay healthy. But I doubt that is the main cause.. It's probably a combination of high PH, ammonia, and no salt.


----------



## Muirner (Jan 9, 2007)

mistergreen - i have had guppies in a 10 gallon, starting at a population of 5 and reproducing to about 30 in a few months with no salt at all. I dont think guppies are a brackish fish.


----------



## t2000kw (Jul 29, 2006)

I would be concerned about the mulm buildup when you set up your tank. If you had enough mulm that you felt you didn't need a soil substrate, that's too much mulm. It would have been better to bite the bullet and do it "right" the first time around, but there's still time if your fish are still alive. 

You might consider moving all fish to a quarantine tank for a while, giving you time to re-do the aquarium with a real soil substrate. Use the water you have now for the quarantine tank, but maybe doa 20% water change up front, then again in a few days. You don't want to shock them with clean water, but there's soethign in there that you need to gradually get rid of. A 10 gallon tank might be enough for a QT tank, depending on how many fish you have, how often you will do water changes (if you're going to overload it with fish, general safe rule is 1 inch of fish per gallon), the amount of aeration you will supply, and how long the fish will be in there. You should find 10 gallon tanks for under $10 in many pet stores. They're almost a disposable item nowadays. You can use multiple 10 gallon tanks if you wish, and they can come in handy when you are bringing new fish home to observe them for disease for a week or so before you put them in with your other fish. 

Then after you've set up a healthy tank with soil substrate and some gravel on top of that, move the fish back to the newly set up tank. You should only have to do this once. You can start with the old water and add it to the new water, but you'll probably want to gradually acclimate the fish to the new water over a period of several hours at the least. 

Since there is a lot more information on the true NPTs with soil bottoms and they generally have a good track record, this might be your best approach, though it may require more work than you wanted to do. However, you seem to care about your fish, so think about it.

Wash the old tank well with salt and water, then rinse thoroughly. Don't use detergents or chemicals, except you can use some bleach if you rinse very well several times with hot (not boiling) water to flush out the chlorine. It should not smell of chlorine when you are done. A couple of tablespoons for every 5 gallons for 1/2 hour should do it. That amount is used to sanitize homebrewing equipment (for home made beer and soda) and rinses out easily. You can also add a few extra drops of dechlorinator for safety's sake.

One thing to be aware of, and that is you may see a temporary nitrite spike 3-4 weeks into the newly planted tank. Test every few days and be ready to deal with this with water changes. Amquel Plus will buy you some time if you need to postpone a water change for a day or so. I don't believe it will change nitrite test results, though, as it only converts the nitrite to a nontoxic form. It still tests as nitrite. 

Once you are through that, you should be good for many months with little or no maintenance if you follow acceptable NPT practices. 

To help you get your tank cycled, the floating plants mentioned (water lettuce, duckweed) are good bets, but don't allow them to completely cover the water. You'll need light to get down to your bottom plants. Once you get some of those plants, they will multiply quickly. We "harvest" a lot every week. The duckweed can be given to our goldfish, but we throw away the water lettuce. 

Try to find some of those plants locally. I could ship you some for the cost of shipping, if necessary, but hopefully someone close by can help you out and get them to you in a more timely manner. You might get some snails or shrimp in the deal, I can't guarantee it till be free of them, but I'll try if you need me to ship you some. PM me if you want to do that and I'll see what I can come up with.


----------



## The Naturalist (Jan 3, 2007)

It is possible that I may be moving within a couple of months or so and am reluctant to go to the trouble of adding soil when the tank will be taken down soon anyways. If it turns out that I will not be moving, I will do as you suggest and add soil. However, I am a bit confused about the difference between mulm and terrestrial soil in the aquarium. Isn't terrestrial soil decomposing plant and animal waste (mulm) with varying amounts of inorganic minerals? Does the difference have to do with decomposition underwater vs. decomposition on the land? 

In the meantime, do you think that I should temporarily return to my pre-NPT routine of monthly water changes and weekly fertilizing? Or is it possible to still have a natural tank and not add soil, at least for a couple of months? I love what the lack of water changes has done for the plants, but I don't want to lose more fish. :|

About mollies requiring salt, I have kept mollies successfully for two and a half years now without salt, and I only just now lost the last of the original individuals. I don't know about the guppies; I had only gotten them a month and a half ago. However, the comment that the plants are using up what minerals are in the water may just be right. For the two and a half years that I have had this aquarium, the health of mollies and plants has seemed to be an inverse relationship. When plants do well, mollies die. When mollies thrive, plants suffer. In addition, I have so far only lost guppies and mollies; no cave tetras or white clouds have died. *Maybe that's it!* Does anyone else think that this is a possibility?


----------



## JERP (Feb 4, 2003)

I do, however I'd repost your question in the fish forum for a better response. Natural aquarium types know much more about soil substrates and patience than fish 

Guppies aren't brackish, but Mollies are. Hopefully, someone in the fish forum would have more expert advice.


----------



## littleguy (Jan 6, 2005)

I think it's a possibility too. Not the only one, but certainly a possibility. Floating plants will suck Ca and Mg (among many other things) out of the water column. If you're substrate is inert (non calcareous) then the GH will drop over time. The only possible inputs of Ca and Mg would be fishfood, which I doubt would be enough to keep up with the plants.

GH and KH would be very easy to test - for example using the 5-in-1 test strips.


----------



## Valley (Feb 28, 2007)

Ok I don't know enough about plants to help you at all there. In fact someone please double check what I say and make sure I'm not going to kill the plants. My goal here is the fish. I'm going to ask you a bunch of questions and I'm sorry but it'll help me figure out what's killing the fish. I know you water stats so we will pretty much skip that. What is your temp set at? How exactly are you losing the fish? What symptoms do they show? Have you seen any fat tummies, skinny tummies, white body patches, damage to fins, bulging eyes, or anything else that just didn't look like a healthy fish before they died? Were they eating and swimming normally? Are there any other tankmates? When you say you recently added the guppies how long ago was that? How much mulm is enough mulm in your opinion? Ok I think that's about it for questions right now. 
The one piece of help I can give you right off the bat is you must get that pH down. Sure most fish can adapt to just about anything you put them in but they won't be happy or thrive. If they are in improper conditions they are far more susceptible to any illness or water problem that comes up. You can reduce your pH safely by over the course of a few days adding small amounts of washed peat to your filter media. Make sure to test your pH daily while you're adjusting it. Too low of a pH is just as bad as too high. I'm sorry this post was so long and so late. Good luck with the fishes.


----------



## t2000kw (Jul 29, 2006)

As for the difference between mulm and soil, I'm not certain of the exact differences. However, we had some 15 year old fancy goldfish. About 8 or so years they had the same undergravel filter without any teardown and replacement, no soil, just gravel over the filter. We lost one, then another of the three goldfish. The mulm went toxic. I don't know why, but it did. We switched to NPT and have had few problems since, and that one fish is still living, along with several other fancy goldfish. That's why I don't like the idea of just using mulm. It also doesn't supply some of the trace nutrients that the soil substrate would provide. 

Now it seems that some mulm in a soil-based NPT is OK. In the normal course of your 6 month (or so) water changes, you will suck up some of this and keep it from building up to a thick layer, so it wouldn't be an issue. 

I don't like the idea of using fertilizers, but you're free to do so if you're comfortable with it. I got into NPT tanks (12 of them) to get away from frequent maintenance. 

If your mulm has gone toxic, DON'T stir it up by trying to suck it up with a siphon hose. That's how at least one of our goldfish got killed. It releases toxic stuff and if the fish comes near it before it dilutes, it can kill a fish. You would need to remove the fish and clean things out, then return them to the tank after adjusting them to the water.

If you want to go real NPT but may be moving, you can do one of a couple of things. You could just switch them to a bare bottom tank for the fish until you move and do the NPT after the move. You could also do the switch to a real NPT with soil substrate now. When you move, move the fish to other tank(s) and drain most of the water the day of the move out of the NPT. Set it up in the new location and fill it with water, then acclimate your fish to the tank again. You may lost some of your nitrification bacteria. You may have to go through the nitrite spike another time but maybe not. I'd keep an eye on the nitrites just in case.


----------



## dymndgyrl (Jan 22, 2007)

The Naturalist said:


> I have kept mollies successfully for two and a half years now without salt, and I only just now lost the last of the original individuals.


Mollies only live about three years. (some say 3-5, but IME it's closer to 3, especially if they are inbred) It's possible they have weakened immune systems from old age, and are dying natural deaths.


----------



## TeutonJon78 (Nov 10, 2004)

It is easy to forget that they are just fish and don't have the longest lifecycles around. I'll probably forget that when my rams reach their limit at 2-3 years.


----------



## The Naturalist (Jan 3, 2007)

The temperature stays about 78 to 80 degrees Fahrenheit. Before the mollies die, they show no external signs of ill health except lying on the gravel more than usual. The guppies didn't even do that; one day they seemed healthy, the next they were dead. The other tankmates are 4 blind cave tetras and 2 white cloud minnows. As for mulm, the gravel is mostly filled but there is little above the gravel except for around the moss and algae in the back corners, where plant debris seems to accumulate a little. In addition, some of the moss at the bottom of the "moss pile" at the back right corner of the tank is starting to die from lack of light.

As for the pH, all of the fish except the guppies were bought when I lived in a place where the tap water naturally had a pH of 8.0. and were chosen because of their tolerance for a high pH. They lived there for several months before I moved to where I am now; here the tap water is at about 7.2. I also read in The Ecology of the Planted Aquarium that the high pH is notsuch a bad thing; it is a sign of healthy, photosynthesising plants.


----------



## Valley (Feb 28, 2007)

Laying on the bottom? Laying on the bottom can indicate a swim bladder or constipation issue. Dying without visible symptoms could be a number of things poor water (tested and ok so not this) TB sure hope not, random illness they weren't strong enough to fight till symptoms showed, or bad blood lines (they are guppies so unless you got them from a breeder this might be it). Also you mentioned tap water. Are you using conditioner, filter, etc? Sometimes water companies will add things to the water that conditioner won't remove. If you continue having trouble that you can't pin point you might want to check on that. I'll not get into the pH thing. If you are comfortable with that I'll leave it be. But please don't rule it out completely. It may be a sign of healthy plants but when the fish aren't well a high or low pH hampers their immune system (sometimes even if it's just a little off). Kinda like if you had the flu and I put you in a walk in cooler; wouldn't really hurt you if you weren't sick but with the flu you are liable to end up in the hospital. Does that analogy make any sense? I promise I won't really put you in a cooler. lol I'm really not seeing an answer here. I just feel like I'm missing a piece of the puzzle. You haven't had anything fall in the tank or sprays that might have gotten in the air have you? No kids sticking their hands in? Used anything new for the plants? Anything like that? Good luck with them.


----------

