Overgrowding /Tunnel

Question
QUESTION: Hi Nicole,

I have a 40g tank with 6 serpae tetras, 8 red eye, 6 black widow tetras and 6 zebra danios and a cat fish(CAE).
Also with some plants  crypts and , an ambrulia and purple.
haze. I have had the tank for 8 months with no casualties.

Q1. Is the tank over crowded with that amount of fish?

Q2. I am considering a Tunnel beneath the substrate,will this effect the bio-cycle? will it benefit my fish?

Q3. I also have an Algae problem for about 2 weeks, I have reduced my light to 8hrs (it was 10-12hrs to promote plant growth)my chinese Algae Eater cannot get rid of it all, I am considering Apple snails, what do you think, any suggestions?


ANSWER: Hi Greg,

That's a nice assortment of plants, I am quite jealous!

1) You are a bit overstocked. The red-eye tetras are tight schoolers, so I can see why you got so many, they also look their best this way. However they are one of the larger tetras, many books say they get up to 5" in length but I've never seen them bigger than about 4". If you had a 55 gallon tank I would say that you were just right.

2) If you are considering the tunnel for your Chinese algae eater, Gyrinocheilus aymonieri, he would probably appreciate it, but he will be equally happy to have some caves made out of rock formations. What often happens with tunnels is that (depending on your substrate) they tend to get filled in, especially with a thrashing fish like a CAE. You can certainly try it, and provided it doesn't make your plants cave in in the nearby area it ought to not be at all harmful. If it doesn't work, you can always remove it. I recommend you use PVC.

3) Apple snails will eat your plants, they love a salad bar! You can try to provide constant veggies such as sliced cucumber, dark lettuce, zucchini, etc. but they will always have a nibble at your plants.

The CAE will eat algae if he has nothing else to eat, but he does not do the job that a bristlenose pleco would do, unfortunately a dwarf pleco will probably also eat your plants. I suggest you look here:
http://www.aquaticscape.com/articles/algae.htm

They suggest lots of algae eaters. Also just typing into Google:
algae eaters for a planted tank
Will return lots of results that you can peruse.

I hope that helps, take care!
Nicole

---------- FOLLOW-UP ----------

QUESTION: Thanks Nicole, thats great advise,
1/With the overstocking the fish seem comfortable, do I have to get rid of some fish? if so how many?
2/will the Tetras hide in the tunnel,(has anyone tried this before)it is made from PVC, will it effect the Nitrogen cycle?
cheers


Answer
Hi again Greg,

1. The fish are probably fine for now. Wait until the red eye tetras grow full size and then see it is too many fish, as I recall they are not especially fast growers. Serpae tetras are known to be nippy, but there are actually three "look alike" fish that are all sold by the name serpae tetra. If yours are acting fine you probably have the well behaved kind, there is only one kind of serpae tetra that nips.

2. PVC is inert, that is why I recommended it to you. It will not leech chemicals or affect your water chemistry in any way. The only way it would disturb your nitrogen cycle, would be if you were using an undergravel filter, which you don't mention having, so I assume you do not have one. If you are thinking to yourself "what the heck is an undergravel filter?" then you don't have one! They used to be a staple in the hobby, but now there is more efficient filtration available.

No one else will hide in the tunnel, you have all surface dwelling and mid dwelling fish with your only bottom dweller being the CAE. Surface dwelling and mid dwelling fish don't hide underground, because they just don't visit the bottom third of the tank very much if at all.

Take care,
Nicole