Stocking and what is this?

I have a fluval flex 15.
8 phoenix rasbora
4 Corydora HABROSUS
14 Neocardina shrimp
2 mystery snail
And 1 what I believed to be a rams horn snail who hitch a ride with a few plants I bought for a LFS.
To Many??
Attaching a few photos to show total set up and the new one who showed up this morning.

Tzano said:

I have a fluval flex 15.
8 phoenix rasbora
4 Corydora HABROSUS
14 Neocardina shrimp
2 mystery snail
And 1 what I believed to be a rams horn snail who hitch a ride with a few plants I bought for a LFS.
To Many??
Attaching a few photos to show total set up and the new one who showed up this morning.

Click to expand...

Hello. A few snails are fine. There are likely more Rams Horn snails than anything else. Don't feed too much and their number will stay small. Too many isn't good. They'll add to the nitrogen level of the tank water and you'll need to change more water and more often to keep the chemistry healthy for the fish.

10 Tanks (Now 11)

First off, welcome to TFF.

Second, don't feel bad about the negatives I will be mentioning. Unfortunately, many if not all of us start out in this hobby taking advice from fish store people, and sadly these rarely have real knowledge so we get led into less than ideal situations. The poor fish are the losers.

First thing to determine is the size of your aquarium. Searching "Fluval Flex 15" I found tanks of 15 gallons and tanks of 15 liters. You are in the USA so am I correct in assuming it is 15 gallons? And the dimensions are 16 in x 15 in x 15 in? Please confirm so we know just what we are dealing with here.

Second, what is the substrate? It looks like a gravel...is it just an inert gravel, or is it some type of plant substrate? This is a critical issue for cory catfish, they must have soft sand. And on the Corydoras habrosus, there needs to be a larger group, in the 10-12 numbers, which may be OK but not without sand. We can go into this more later.

The Phoenix Rasbora, is this the species Boraras merah? They are fine in this tank, a few more wouldn't hurt.

This brings me to the water parameters. Do you know the GH (general hardness) and pH of the tap water? You may be able to find this data on the website of your water authority if you don't already know. This too can be critical for small sized fish species.

The plants are having difficulties, do you use any fertilizer, and if yes, which one(s)?

The substrate is called shrimp sand. I had fluval stratum in the tank originally but could not keep it clear. Yes the it is 15 gallons US. 15x15x16 is correct. Yes Boraras Merah! I do not use tap water anymore it is extremely high ph out of the tap. My water perimeters. Are as fallows :
Temp 74.4
PH 7.4-7.6
KH 5 degrees
GH 7
Ammonia 0
Nitrite 0
Nitrate 10 ppm
I use Easy Green fertilizer once a week
Would also say I remineralize my what with salty shrimp GH/KH+

Photos of my mystery snails already pulled one bunch of eggs off of tank lid!

Byron said:

First off, welcome to TFF.

Second, don't feel bad about the negatives I will be mentioning. Unfortunately, many if not all of us start out in this hobby taking advice from fish store people, and sadly these rarely have real knowledge so we get led into less than ideal situations. The poor fish are the losers.

First thing to determine is the size of your aquarium. Searching "Fluval Flex 15" I found tanks of 15 gallons and tanks of 15 liters. You are in the USA so am I correct in assuming it is 15 gallons? And the dimensions are 16 in x 15 in x 15 in? Please confirm so we know just what we are dealing with here.

Second, what is the substrate? It looks like a gravel...is it just an inert gravel, or is it some type of plant substrate? This is a critical issue for cory catfish, they must have soft sand. And on the Corydoras habrosus, there needs to be a larger group, in the 10-12 numbers, which may be OK but not without sand. We can go into this more later.

The Phoenix Rasbora, is this the species Boraras merah? They are fine in this tank, a few more wouldn't hurt.

This brings me to the water parameters. Do you know the GH (general hardness) and pH of the tap water? You may be able to find this data on the website of your water authority if you don't already know. This too can be critical for small sized fish species.

The plants are having difficulties, do you use any fertilizer, and if yes, which one(s)?

Click to expand...

I would love any recommendations for my plants you may have. I have even thought about adding another light for them.

Tzano said:

The substrate is called shrimp sand. I had fluval stratum in the tank originally but could not keep it clear. Yes the it is 15 gallons US. 15x15x16 is correct. Yes Boraras Merah! I do not use tap water anymore it is extremely high ph out of the tap. My water perimeters. Are as fallows :
Temp 74.4
PH 7.4-7.6
KH 5 degrees
GH 7
Ammonia 0
Nitrite 0
Nitrate 10 ppm
I use Easy Green fertilizer once a week
Would also say I remineralize my what with salty shrimp GH/KH+

Click to expand...

Parameters are generally OK for the two fish you have, just make sure the GH does not get any higher. For the fish it would certainly be much better to not remineralize. I understand about the shrimp, but the fish are involved.

Nitrate at 10 ppm...is this occurring within the aquarium? I assume so, if you are not using tap water (nitrate can sometimes be present in tap water). I would work to get this down though. The plants can help with this. And more water changes, and less feeding.

The Easy Green should be OK, but when it is gone there are better products. We can discuss later.

Now to the most important issue here, the substrate. I would not keep cories over this. Cories are sand filter feeding fish, there is sand (or mulm/mud) in all cory habitats, and they take a mouthful, filter out any food, and expel the sand out the gills. They cannot do this with any thing but soft sand. Also, these larger grain substrates cause serious bacterial issues that sand does not. If this were me, I would exchange the substrate for sand. I changed all my tanks over some years ago, and have never regretted it.

The Nitrate is occurring with adding easy green fertilizer it will drop over the course of a week. To less than 10 ppm. I used the shrimp sand only because of the shrimp. After watching a lot of YouTube videos I wish I had done some sort of black sand. Any recommendations for a black sand substrate? I have to remineralize my water as I use RODI water now.

Tzano said:

The Nitrate is occurring with adding easy green fertilizer it will drop over the course of a week.

Click to expand...

This is interesting. I spotted the 2+ % nitrate in the ingredients of Easy Green, but would not have thought it would do what you describe. I would get rid of this fert and switch to Flourish Comprehensive or FlorinMulti. I have used the former for 12 years and never had nitrates rise above the 0 to 5 ppm range. With fish in the tank plants will not take up nitrate unless ammonia/ammoniuum (their preferred source of nitrogen) is seriously lacking in balance with everything else. It takes them roughly 24 hours to "switch gears" to use nitrate, and then have to change it back into ammonium in order to even use it. Seachem have reduced the "nitrate" in their product, and there is in England TNC Lite which has none. [Same holds for phosphorus, this should never be added, there is enough in fish food for most planted tanks that are low-tech.]

Your water changes, fish stocking, and fish feeding should mean nitrates remain stable through the week; depending upon stocking they may rise a tad, but in my tanks over 12 years--and they were pretty well stocked--nitrate never rose above the 0 to 5 ppm range. I've no idea if nitrate varied within this, but it never got over 5 and I was satisfied with that. Nitrate does affect fish, it is just slower to act, and it depends upon the level, the fish species, and the exposure time. It is now believed that it slowly weakens fish, making them more susceptible to other issues along the way.

On the black sand, this is a problem for cories too. It causes stress as they attempt to darken in order to be inconspicuous. The reverse happens over white sand. Neither should ever be used in a tank with substrate fish, I would not be surprised if loaches might not have this problem too. When one studies the habitats of all cory species, one thing that is evident is how they blend into the substrate. This is no accident of evolution. I had black substrate in a tank with panda cories many years ago, and when I moved them into a sand tank I readily noticed the change in their colouration. I was not aware of the issue back then, but in hindsight it was clear proof of the problem.

I do 2 pumps of easy green a week so it raises it buy 6 from what it says on their site 3+ nitrates per pump. So it would be 4 ppm before adding the easy green. I may look into another way of giving the plants food differently like possibly root tabs for the ones that are planted. I am going to stop feed so much also. I believe I have been over feeding. This is why my mystery snails have doubled in size in just 2 months. Not sure what substrate to use to make the Corys the happiest and also keep the plants happy also. Definitely open to suggestions.

Tzano said:

Not sure what substrate to use to make the Corys the happiest and also keep the plants happy also. Definitely open to suggestions.

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This is easy to answer. Soft inert sand. You can buy expensive aquarium sands, just make sure they are not white or black and are inert, or you can use a quality play sand (but not any other industrial sand when cories are involved). I used Quikrete Play Sand, available at Lowe's and Home Depot in NA, probably elsewhere too. But it is good sand, I discussed it with Quikrete some years ago. To my knowledge, I never have had issues with this sand in all my tanks since I changed them about 8 or 9 years back.

Plants grow as well as they possibly could in this substrate. I used black Flourite several years ago, and within a week the cories had no barbels and one had a third of its lower jaw sliced off. Moved them to a play sand tank, the barbels regrew and the panda with part of its jaw missing lived for many years, comical to look at but able to eat. The sharpness was a factor, but I suspect the bacterial issue that is pertinent with all plant substrates was another.

Flourish Tabs are one of the best plant additives available. Somehow they do not release nutrients into the upper water column, which means you cannot realistically cause algae issues like you can with overdosing liquid fertilizer. And plants like swords and red tiger lotus really show the benefit of these tabs.

I was also thinking the play sand. I used it for my reptiles years ago for egg laying bins. Thank you so much for the info on the Flourish tabs!
So I am concerned I have over stocked my little 15 Gallon tank. I have had no issues with it other than issues with my plants. I would love to increase by 1 or 2 Corys and 4 more rasboras but I am not sure that would be wise as the tank is only 15 gallons.

Tzano said:

I was also thinking the play sand. I used it for my reptiles years ago for egg laying bins. Thank you so much for the info on the Flourish tabs!
So I am concerned I have over stocked my little 15 Gallon tank. I have had no issues with it other than issues with my plants. I would love to increase by 1 or 2 Corys and 4 more rasboras but I am not sure that would be wise as the tank is only 15 gallons.

Click to expand...

OK, let's discuss stocking. This is a topic misunderstood by many in this hobby, beginners anyway. We think of fish mass to water volume as being it, but it is not the real issue. Obviously the fish species must be suited to the aquarium in all integral respects, meaning sufficient space for swimming for that species, the correct water parameters, the right aquascape so the fish have what they inherently need in their lives, and of course compatibility.

The C. habrosus must have 10-12 absolute minimum, and the sand. This is crucial to their health because studies have now proven that shoaling fish in smaller groups have problems: usually increased aggression but sometimes the opposite withdrawal to the point they die, and a latency to feed. This is obviously serious stuff to the fish, if it is reluctant to eat because of the effect of insufficient numbers of its own species. So providing adequate numbers is actually lessening the fish's impact on the biological system than would be the case with fewer of them. It is how fish live. I had the closely sized C. pygmaeus in a 10g for a few years, a group of six which became 30 with the fry that grew, and they seemed perfectly well. I also had a 10g tank with sand, no filter, lots of plants, with 12 Boraras brigittae and 10 C. pygmaeus. There was room for more of both had I wanted to, but it was an experiment to see if a tank could be self-supporting in a sense with no filter and no light (south-facing window). It worked, the plants were thriving, the fish too for all I could tell. It was another case of providing what the fish consider essential.

Your 15g is a cube, but that is ideal for both of the species you have. Neither are active swimmers that need length for swimming relays. They cruise around, the cories examining ever surface for food bits. With sand and floating plants, this will be the ideal habitat tank.

I have been thinking red root floaters for sure! The Corys do a ton of exploring and love the plants a wood! The rasboras were only 4 and I place 4 more in and they seemed a bit happier. I would definitely love to have 4 more just to help them school and give them a since of security. The Corys I absolutely am in love with and would love for them to have a couple more friends.
I have the 3 snails also who I would prefer not to have any more than the ones who already there. I am just looking to make sure I am not putting too much in the tank. I don’t mind checking level and doing water changes.

Tzano said:

I have been thinking red root floaters for sure! The Corys do a ton of exploring and love the plants a wood! The rasboras were only 4 and I place 4 more in and they seemed a bit happier. I would definitely love to have 4 more just to help them school and give them a since of security. The Corys I absolutely am in love with and would love for them to have a couple more friends.
I have the 3 snails also who I would prefer not to have any more than the ones who already there. I am just looking to make sure I am not putting too much in the tank. I don’t mind checking level and doing water changes.

Click to expand...

Sounds good. You are not overloading if the two species have sufficient numbers to be healthier. If this were my tank I would probably have a third and maybe even fourth species, also in groups around 12. Wouldn't worry about the snails here.