Breaking the biotope...

[Wills]

Hi so as some of you may know I am about to start restocking my tank and I thought I would share my plans and see if anyone has any advice or anything to add.

The tank is 135 gallons (512 litres) 6x2x18 and has 2 FX6 filters on it. Ph of 7.1 and a hardness of 19dGH - Nitrates are 40ppm out of the tap so I do my best with water changes and filter cleans but it is what it is unfortunately.

I've been chatting to a few people on the forum and gained some valuable insights to an aspect of the hobby that I had not really paid too much attention to in the past which is, water hardness. Shocking I know but when I was setting my tank up and building my community it was just something we did not take into consideration when planning stocking levels - Africans needed high ph, Discus needed low ph and everything else was just sort of fair game. However after an insightful chat with Byron I am now onboard with taking this into consideration.

So that said, with my slightly above neutral and quite hard water I have decided to restock my tank with Central American Cichlids.

My main two groups will be Nicaraguans and C.Nanolutus both fish that I have wanted for a long time. As you will see from my profile picture I did have a female Nic for a number of years but she was unfortunately killed by a Severum I tried to add to the tank when she was 2 years old. I tried adding some other Nics but the first female I added was very fiesty for the South Americans I was keeping and I later tried a male but he brought in a disease that took out a lot of my 'prize' fish which was a bit devastating to say the least.

I've been advised that Nics actually do really well in a group and it can help keep their aggression under control, so I am thinking of having a group with 1 male with 3 maybe 4 females. I am then considering adding 2-3 pairs of C.Nanolutus, being small and quite timid compared to regular Convicts the extra numbers should help them gain some confidence.

As tank mates my natural asumption is to look for other central american species that will do well in my tap water but I am hitting a deadend. I have a wide variety of livebearers as options and I am weighing up my options there, I am thinking of a small group of wild type sword tails or maybe one of the rarer swordtails like X.Montezuma or maybe some of the rarer Molly types? But other than that I cant find any tetras or catfish I am likely to encounter in shops in the UK.

So, I had an idea to look outside of Central American 'biotope' and have started to think about a group of mid sized Synodontis. Something like S.Petricola or I have seen some videos of an S. Polli 'White' which look great but I am not sure how common they are even among specialist shops... but I might try and keep an eye out.

But this is quite a departure for me as in the past I always kept fish from the same sort of region, previously I kept just South Americans so I am finding it a bit unsettling. But since they both have similar requirements and Synos are commonly kept with African Cichlids I sort of feel this should work?

Has anyone kept similar species together before with success? Let me know your thoughts on the other fish as well.

Thanks Wills

 

[AbbeysDad]

All due respect to Byron as his knowledge and success in the hobby is near legendary. I too sought him out when I first dipped a toe in the planted tank.
But like all of us, Byron has a mindset about fish and their native habitats and what's best for them. However, many/most of the freshwater fish we see in the hobby are born and raised in ponds and tanks, far removed from native habitats. Oh some are still wild caught and shipped, but they are exceptions rather than the rule. As such, most of these fish are accustomed to a wide range of water chemistries when it comes to hardness and pH.
I'm more concerned about the high nitrates in your source water. Starting at 40ppm nitrates, this will only increase even in a heavily planted tank with minimal stocking levels.
I too have high nitrates in my well water. I fashioned a DIY nitrate filter by re-purposing a now discontinued API Tap Water Filter filled with API Nitra-Zorb. The filter yields 200g before the media needs to be recharged with salt water. So obviously I prefilter water for weekly partial water changes.
Since your water is too hard, you might 'cut' with distilled or RO water, which will also reduce your nitrates...but they would still be too high to sustain healthy fish long term. You might look into a means of culturing anaerobic bacteria to convert nitrates into N2 gas, but this is no small feat.
Keep posting and let us know how you're making out!

 

[Wills]

Hi yes I agree it is less than ideal, I believe it is because our water comes from a series of natural resevoirs, lakes and ditches and I imagine I am not alone in the UK in this situation.

I have looked into a number of ways to reduce Nitrate but I dont see any of these as a long term option as changing around 200 litres at a time storing the water isnt really an option for me.

When it comes to the tank, the tank is around 8 years old now and a lot of the fish were moved from smaller tanks I had had for a few years previously. I lost a severum some time last year that I had for around 8 years and her previous owner who would have had her in the same water had her for 4 years so she was at least 12, she was a Heros Severus so the smaller mouth brooder which most places state as a life span of 10-15 years. This is just one example but I've had a number of fish that have lived well into their expected life span. As I mentioned above I lost a lot of fish around 2012 to a disease outbreak but up to that point most of them were 3-4 years old and were really healthy colourful specemens.

Im not disputing that high nitrate is an issue but I believe that I manage it quite well and that Im able to raise long lived healthy fish as a result.

Wills

 

[hobby5]

Hi Wills!

I understand your deadend But I would't add any bottom dweller. Central American cichlids are not used to them and are usually pretty aggressive towards them. So the "standard" is cichlids and live-bearers.

I know you really love the Nics, but imho the tank is too small for them. Rule of thumb is the largest fish should not be longer than 1/10 of the tank length and male Nics will easily exceed that. Also as you experienced they can be pretty agressive. I have heard of cases where the male killed the female and some Thorichthys meeki and Cryptoheros saijca in an slighty smaller tank (20 cm less) tank than yours. Also the combination with the C. nanoluteus will not work, those will simply lose out. So I highly recommend to go for a different species.

About the nitrates, I am with AbbeysDad. They are harmful for the fish and should best be 0. So you need to find a way to reduce them. Many plants can help, but are usually difficult to maintain in a cichlid tank.

 

[AbbeysDad]

Regarding the nitrates in source water, this is also common in the US in agricultural areas, the result of fertilizers. I have a 95 acre farmers field across the road from me.
You could see some benefit from pouches of API Nitra-Zorb in your filter(s). The resin adsorbs nitrates and the pouches can be recharged in non-iodized salt water and reused several times. This would help in lowering nitrates.
Additionally you might look into plants known for being nitrate sponges. Anacharis comes to mind although other (especially floating) plants may also do a good job of reducing nitrates and purifying the water.

 

[Wills]

Hi both thanks for getting involved.

Im really aware of the issue with nitrate in my water and its not that I disagree with what you have said but... I think saying that nitrates should be 0 is just not achievable and is an unobtainable goal and realistically for me, unnatural. Nitrate must surely be present in all natural fresh water (hense why it is in my tap water for starters) so to say that above 0 is harmful for fish is just unatainable.

Equally if I wasnt at the end of what I would call a 10 year project with a South American tank where I've successfully kept a number of fish to around or beyond their natural life expectancy I would be more panicked by what you have said. Not only have most of my fish (aside from obvious disease outbreaks) lived what I would call a decent life a number of them have regularly spawned, just about every female cichlid I've kept has laid eggs, with or without a partner. This includes my Heros Severus, one of my nicaraguans, a young Thoricthys sp.Mexito gold (Spelling), 2 pairs of Laetacara Thayeri, Cupid cichlids which I had as a group, a Honduran Red Point pair I had when I first started keeping fish. I've had a pair of Sturisoma lay eggs, I had a large group of Annostomus Ternetzi that used to breed all the time - especially once they were all a few years old. I had a large school of Lemon Tetras I used to see scatter eggs regularly. Not many of the eggs survived as it was in a community tank, when 2 of the Annostomus spawned the rest of the group usually hovered under neath and ate up what was scattered.

So what Im trying to say is that while I respect and appreciate your advice I do think you are being overly cautious. I like to think that I am a responsible fish keeper and I like to think that I have been doing a good job for the past 10 years despite having the issue with 40ppm Nitrate in my tap water. I have had decently planted tanks in the past which I imagine has helped, at the moment I am plantless as I have a young Uaru in there which decemated a hugmongous Java Fern I had.

I also have to disagree with what was said about the suitability of a male Nicaraguan in my tank, based on the size. By what you are saying I would need a tank in excess of 8 feet to accommodate the max size stated for a male which is 10 inches, and for me 10 inches is something of a rarity. And on this basis it would discount the majority of 'average' cichlids from being kept in most tanks. There have been many members on here that successfully kept things like Oscars and Severums (H.Efasciatus), common species that regularly attain at least 10-12 inches in tanks of a similar size to mine. Most of the respected profile sites state much smaller tank sizes than 8 feet for the majority of large cichlids, obviously some exceptions would be things like Persei and Bocourti and some of the massive True Parrots you get.

I sort of agree with you on the aggression front, but thats with all cichlids and its just something of a risk that is up to us to manage. I am debating on if I just want to do a group of female nics, Ive been speaking on a few forums and facebook pages about this and I have had a number of people say that when kept as a group rather than a pair or a single fish Nicaraguans are much more chilled out, and again this is people backing this up with tanks that have been running well for a few years. The other thing with Nicaraguans is that while they can be bolshy and showy they have absolute nothing to back it up, so I still think keeping them with something as mellow as the Nanoleutus is an option because the nanos will probably not stand up back to the nics which will hopefully create a hierachy pretty quickly where as keeping them with cichlids that could stand up back to them it will inevitably spiral and lead to damage and regular conflict.

Thanks for the replies
Wills

 

[Byron]

Im really aware of the issue with nitrate in my water and its not that I disagree with what you have said but... I think saying that nitrates should be 0 is just not achievable and is an unobtainable goal and realistically for me, unnatural. Nitrate must surely be present in all natural fresh water (hense why it is in my tap water for starters) so to say that above 0 is harmful for fish is just unatainable.

First, the nitrate level in natural habitat waters for all the fish we maintain is basically zero. No tests of habitat waters have found nitrate present at a level above 1 ppm, at least I have not seen any [if anyone has, please post]. So there is no question that tropical aquarium fish in nature are exposed to nitrate, any more than ammonia or nitrite. These simply do not exist in habitat waters.

It is true that ammonia, nitrite or nitrate can occur in some waters as the result of pollution or agricultural runoff. But that is a very different thing, and not surprisingly, the fish would most likely all be dead. Some temperate polluted waters (with nitrate) might have certain fish species, but again we are not talking about any of our aquarium fish.

Second, the toxicity. Ammonia, nitrite and nitrate are all forms of nitrogen, and all are seriously toxic to fish. Ammonia and nitrite act more rapidly as we all know. The toxicity if nitrate is not as well studied, though that is changing. But all the scientific folks do agree that the higher the nitrate, and/or the longer the fish is exposed, the more detrimental. And some species are more sensitive than others.

Another aspect of nitrate's toxicity is what it actually does to fish. Here again there is less data than for ammonia and nitrite. I had a good exchange with Neale Monks on this topic a few months back, when it was raised in another thread. Neale suggested that nitrate is most likely to act as a weakening toxin, weakening the fish's physiology and affecting the metabolism. This might go on for years before the fish finally dies, and the direct cause of death could be almost any disease. But the slow weakening of the fish caused by nitrate would be the underlying cause. If you have ever read any of Neale's advice to questions regarding nitrate in TFK or other periodicals, or online, you will have noticed that he recommends keeping nitrate below 20 ppm. [He confirmed to me that this is using our aquarium test kit, like the API.] Some fish are more sensitive than others; wild caught fish for example will have more difficulty adjusting, though that does not mean that simply raising fish commercially somehow minimizes the risk. And cichlids are especially sensitive to nitrate. Cichlid sources are now recommending nitrate be kept below 20 ppm, and as low as possible, and some are suggesting that issues like Malawi Bloat are more likely due to nitrate than diet as used to be thought.

The bottom line is, nitrate is toxic, and it should be kept as low as possible, certainly under 20 ppm to be safe.

 

[Wills]

Ok I give in...

What do I need to do?

Turning to something like RO and that process isnt an option for me due to circumstances at home, happy to add a lot of plants, Im pretty confident I can keep up a decent amount of plant life even with cichlids given the ones Im after are none herbivourus. I'll just need to stick to things like Java Fern that dont root in the substrate.

But surely each time I do a water change Im going to end up creating a spike in nitrate if I am managing it within the tank?

Wills

 

[Byron]

Abbeysdad has dealt with very high nitrate successfully, so I will leave it to him to explain the workable options. Dealing with nitrate occurring within the aquarium is relatively easy, as we can control the sources (fish, organics, plant additives). Nitrate in the source water is more involved.

I will however comment on plants...generally this is not going to have much effect. If you had a heavily planted tank with mega light and diffused CO2, there would be a considerable need for nitrogen to balance, and aquarists add nitrate to supply this, so the plants would use some of the source nitrate. But in more low-tech or natural tanks, the plant's use of nitrate is very low, as I'll try to explain.

Aquarium plants need nitrogen obviously, but most species prefer it as ammonium (ammonia), and they can take up a lot of this. There are a very few known species that seem (from experiments) to prefer nitrate, but most like ammonia/ammonium. At this point, we bring in the balance of light/nutrients. The light intensity (if the spectrum is correct too) drives photosynthesis, but all the required nutrients must also be sufficient. If any one factor is missing, photosynthesis will slow and even stop, depending. So the plants' uptake of ammonia/ammonium will to some degree be governed by the other factors of light, other nutrients, fish load and plant species and numbers. Having said that, plants can store ammonia/ammonium. Fast growing plants can use a lot of ammonia; floating plants are often referred to as ammonia sinks, for this very reason, and this is why new tanks will cycle "silently" when fast growing plants are present and fish are added at the start.

So the point of the above is that with plants using most of the available ammonia, very little gets past them to the Nitrosomonas bacteria, which in turn means very little nitrite results, which in turn means very little nitrate. So the prime reason plants are considered good for nitrate is not so much because they take nitrate up, but more because their uptake of ammonia means there is very little nitrate resulting. It is possible to have zero nitrate in reasonably planted low-tech/natural planted tanks for years. The fish load really governs this; the more fish, the more organics, and the more likely nitrate may result. [I'm being very general, there are other factors at play.]

So with high nitrates in the source water, unless it is a heavily planted high-tech system, plants are not likely to use much nitrate, depending upon the level of ammonia/ammonium occurring. Plants only turn to nitrate when ammonium is insufficient in balance. This is because when these plants that prefer ammonium take up nitrate, they must use valuable energy to change it back into ammonium in order to utilize it. Plants have the "wisdom" to know this is not helpful, as it means energy is being diverted from growth and reproduction, so they turn to nitrate as a sort of "last resort." There is also some evidence that they will take up nitrite before nitrate, but this has not been as well studied, but it might be one more hurdle to their use of nitrate.

So, dealing with the nitrate in the source water before it gets into the aquarium is the way to go, and as I said, Abbeysdad can advise on that. This also answers the question about water changes. If some nitrate is still present, using Prime as the water conditioner will temporarily help, because it is the only conditioner I know of that detoxifies nitrate when in the source water; it does this (according to Seachem) by somehow binding it, similar to how it detoxifies nitrite. However, this is temporary; in 36 or so hours, any nitrite/nitrate present in the bound form (non-toxic) will be released and again become toxic.

Byron.

 

[hobby5]

Hi Wills,

I am very glad that you share your experience with us. It is somewhat puzzling to me as it doesn't fit my expectations. So it would be interesting to know what were the final water parameter in your tank. Also, plants can eat a lot of nitrates, so this might have helped you. The other thing I am curious about would be KH. This often seems to be more important than GH.

Successful reproduction of fish is by no means an indicator of good living conditions. Many will breed under pretty bad conditions.

Concerning tanks size. Yes many cichlids are kept in way too small tanks and most of the species profiles are simply wrong. Maybe you can keep a single cichlid or a matched pair in smaller tanks but what you plan on is a community. And if the aggression in your tank is too high it simply tells you that you are keeping too many fish in not enough space. You don't want a hierarchy, you want sufficient space for all. Why have the C. nanoluteus at all, if they have to live under the constant pressure of the Nics?

If you chose some smaller species you could provide a great environment for all of them as you got a really lovely tank size.

I absolutely don't like keeping fish in single sex groups. You deprive your fish (and yourself as observer) of a lot of natural behaviour. Also the best colours often only come out in breeding mood.

Just my 2cents

 

[AbbeysDad]

As Byron points out, plants prefer ammonia as their N2 source which indirectly reduces tank generated nitrates. This has incorrectly convinced many that plants (especially floating plants) consume nitrates.

I've thought about high nitrates a lot and I think to a point, nitrates gets a bad rap. In the aquarium, we use nitrates as a measure of pollution. However, along with nitrates, there are other elements of pollution like proteins, carbs, fats, pheromones, acids, etc... It is these combined pollutants that negatively affect the stock. Now although our source water may contain higher than desired nitrates (due to Ag fertilizers), the partial water change flushes out and dilutes [all] the tank pollutants. So although it would be best to have nitrate free water for water changes, water with nitrates is still valuable at reducing the pollution.

But with high (40ppm or higher) nitrates in the source water, we need a way to reduce this as well as keeping tank nitrates lower (e.g. proper feeding of high quality food, good filter/tank maintenance).

I pre-filter water for water changes to remove nitrates. My DIY filter works great, but there are inline filters (used for refrigerators & ice makers that remove nitrates.

In the aquarium filter(s), I have had success with API Nitra-Zorb pouches. They can last for a couple of weeks and can be recharged several times with salt (aquarium or non-iodized table salt) water. The 'trick' is to place the pouches after fine filter material to reduce detritus from coating the resin pellets and shortening it's use life). There is also a product called Allgone, but I have not used it.

There are medias like Seachem Matrix/DeNitrate, MarinePure CerMedia, and others that claim to serve as a platform for anaerobic bacteria to convert nitrates into nitrogen gas. I haven't totally given up on this but so far I have found it challenging in the oxygenated FW aquarium to culture the Anaerobic bacteria!

 

[hobby5]

Yes plants prefer ammonia, but they can and will also use nitrates, if no or not enough ammonia is available. Btw, many fertilizers contain nitrates.

 

[Wills]

I've had this recommended to me which I think could be a solution

https://www.pozzani.co.uk/product_info.php?products_id=157&q=Twin

This should hopefully remove all nitrates from my tap water, its got great reviews and the person that recommended it to me is using it now. I just need to wait a little to invest in it as my job is a little volatile at the moment.

I also need to work out if I can run water from a mixer tap through it or if it can be just cold water, Im hoping I can run it at at least room temperature and then top up with kettles and maybe put some heaters in, I always have 2 spare 300w heaters in the house just in case so they will have a use.

I will still potentially have plants in the tank as well, just low maintenance stuff so hopefully that should be enough as to not have to use extra materials in the filters?

Hobby5 on the fish you have got me doubting my decision a bit with the Nics, Im really not against keeping just females as breeding is not my main focus but I understand where you are coming from. At the moment though nics have slipped on to my maybe list. I definitely want the Nanoleutus as Ive wanted them for a long time and I also want a group of Synodontis Polli 'White Zambia' I think these two could work well together, my tank has a large piece of wood in that creates lots natural shelves and caves so I do think it will work. I think I will probably still add in some live bearers not 100% what I want, it may depend what i can find as I dont just want to go with the standard swordtails or mollies etc, but I do like natural type swords...

What other species would you include in a tank like this?

I do have to say though, Im still not sure I can agree with you on the tank size with larger cichlids. Ive met many, many highly respected fish keepers across the UK keeping larger cichlids like Chocolates, Severums, Oscars, big Centrals, Uaru, big Geos and Satanopercas and others in 4-6 foot, 100-180 gallon tanks with great success.

Thanks for all your help and suggestions so far everyone it is much appreciated.

Wills

 

[hobby5]

I do have to say though, Im still not sure I can agree with you on the tank size with larger cichlids. Ive met many, many highly respected fish keepers across the UK keeping larger cichlids like Chocolates, Severums, Oscars, big Centrals, Uaru, big Geos and Satanopercas and others in 4-6 foot, 100-180 gallon tanks with great success.

I know where you are coming from. It used to be like that, but hopefully things are improving over time. Ask them, what else was in the tank beside the breeding pair and then ask them how often they lost the female...

If you ever saw those cichlids in a really large (public) tank, you will understand the difference. For me it is just no fun anymore to see those high aggression levels, due to space constraints. That also means a lot of stress for the fish and that will affect their health in the long run.

You got a lovely tank size and could create something beautiful if you choose your fish a number smaller If that was my tank I would go even smaller and choose something which roughly does not exceed 10 cm like A. thomasi, Pelviachromis, Laetacara, Nanacara, et. Just to name a few, there are many more. (ok, many are not suitable for your very hard water.)

If you are looking for something comparable in size to the C. nanoluteus here are a few ideas:

Herotilapia multispinosa (also yellow)
Any of the smaller Thorichthys
Andinocara pulcher
Cribroheros longimanus

 

[Wills]

And now I can see where you are coming from the tanks I mentioned were generally community tanks with large fish and it was generally single sex single fish but like you say when breeding was involved then in most cases it would not have worked.

Its funny that you mention going for the dwarfs because one of my first inclinations for the tank was to do a very large group of Discrossus (Checkerboards) maybe with some Laetacara Dorsigera and build a community around them but as you say my water is not suitable for them. A shop near me always has the most amazing checkerboards in, there must be a breeder locally.

Thanks for the list Ive never been a huge fan of Rainbows, I've looked at a few of the Thoricthys before but not sure. I didnt realise Blue Acaras would be an option but they have quite a wide distribution right? I like the Cribroheros, not heard of those before (which is always a plus ) so will have a read up. A lot of Centrals have just been renamed right?

One fish I have always wanted to keep is Theraps or Rheoheros Coeruleus - I believe these like fast flowing water. I've just looked and seriously fish lists Nanoleutus as living in moderate to fast flowing water as well, which could make them possible contenders? They are a fair size for this kind of tank as well, most sites state them as reaching 12-15cm. The flow from my filters is quite strong, I have had trouble keeping floating plants because of this in the past to give you an idea of flow, but I could look into powerheads if required. What do you think?

I know what you were saying about the male Nicaraguan outgrowing the tank and causing issues if breeding but what do you think to just a group of females? I know you said about wanting to see the natural behaviour but if this was not the priority for me do you think it could work? From what I have seen/heard groups of Nics work better with other fish once a hierachy is formed between them.

Thanks again

Wills