5 Substrate Questions

[Regan]

I'm setting up my first serious cories only tank - 11 juvenile emerald cories plus 9 laser orange cories; 75 gallons. If somebody can provide feedback for us on the following 5 substrate questions, that would be excellent and much appreciated:

1- Is it true that gravel substrate erodes cory barbells?
2- Even the smooth, coated gravel?
3- Would sand be better?
4- If so, can anybody recommend a good sand?
5- Also, Is there anything to worry about with sand? (Susceptible to fungus? Difficult to vacuum / keep clean?

Please let me know. Thank you

[MarlonnekeW]

I've had cory's on both rounded gravel and sand. In my opinion sand is better. My cory's were doing fine on the gravel, but with sand they display different behavior; they put their nose in to search for food and put the sand through their gills to filter out small food particles. This is not possible with gravel.

In the Netherlands we have a big chain, similar to Home Depot, that sells 'sand' that is 0,4 mm - 0,8 mm in different colors (for example black or brown). Of course, I've no idea if a similar product is being sold in Canada. This sand is great, because it won't become silted up. This could be a problem with regular aquarium sand. To avoid this, a lot of people also use filtersand that is used for pools.

[Regan]

I am currently setting up a second tank for a family of Geophagus Iporangensis (cichlids). Geophagus means "earth eater" because they sift sand when they feed. Consequently, I for sure have to provide them with a sand substrate for this. 3 years of raising cories I had no idea they are also Earth Eaters! That is really interesting. Thank you MarloneekeW!

Sand is starting to feel like a good fit for us. I would feel better if it promises to be a soft edged sand though and not sharp edged and abrasive.

Can anybody help me zero in on such a thing?

[PseudaSmart]

Please provide more information to get best answers. What size tank and what type of filtration do you plan to use?

What looks good in a book may not work long term. Example: a 180 gallon tank with an FX5, sand base, and large plecos = BAD IDEA! Sand gets moved / dug up, gets sucked into filter, clogs filter, and sand destroys impeller.

Jim

[TwoTankAmin]

I am going out on a limb here and basing what I say on my memory of a few older posts here, my experience and a few external sources.

First, cory barbels help the fish locate food, and they are somewhat delicate. They have a downward facing mouth and eyes that don't see well for seeing food on the bottom. As far as I can tell, corys suck in food once they are on it. In the wild corys are found eating on sand, pebbles, and rock bottoms. I have seen the videos. In tanks, we also can use bare bottoms. All of this relates to substrate.

It is only possible for corys to suck in some substrate with their food if it is fine enough, such as sand.

I have done fine keeping corys, including some limited spawning thereof, on fine gravel and bare bottom tanks with decent results in terms of barbel health. But my experience is only a few species over a number of years ago. I am not trying to say these methods are necessarily the best but they do work.

The worst thing for corys barbels is to "force them to have to forage deeper into the substrate. Their barbels are for locating food that doesn't mean they have to go deep to get at it. In sand and fine gravel in a tank, the food is easy to get. But. as the size of gravel gets larger, the more spaces there are and the larger as well. Food slips deeper. The cory barbels sense it, however, trying to reach it exposes them to rough surfaces and/or edges. Such deeper and abrasive foraging damages barbels which in turn opens them to futher issues and suddenly they are very short or even gone. In addition, things that sink a bit into bigger gravel bottoms tend to be in a place where some not so good stuff is also found. Stuff we don't really want corys rooting around in.

So the upshot is that for most tanks, sand would be the most ideal option and finer gravel an acceptable alternative as long as it is not allowed to accumulate gunk. Sand gives one the opportunity of seeing them sift it which fine gravel won't.

Bare would be fine for folks trying to spawn them or when they are being help shorter term.

Avoid anything bigger than fine gravel. There is no upside and lots of downside. Also, avoid exposing cory barbels to unhealthy things where their barbels work, i.e, keep a healthy substrate where they feed. In the wild, nature tends to do this with current and by providing a much greater area where they can forage.

If I have gotten any of this incorrect, I am hope the real cory experts will chime in and correct me.

[MChambers]

Most of my corydoras tanks have sand. I usually use pool filter sand. It may not be as fine as the corydoras would prefer, but it is heavy enough so that it doesn't get sucked up into filters. It's also inexpensive, about $9 for a 40 pound bag.

[bekateen]

Playground sand from Home Depot or Lowe's (in the USA) works great with corys, but it's so fine it gets sucked into powerful filters and can damage impellors and other mechanical parts. But my corys love it. So if that is a concern, then a fine gravel (1/2 - 1 mm) is better than sand. I read on another thread that if you buy any sand or fine gravel of unknown type, then rub some between your fingers-if it hurts, then it is too "sharp" and could harm the corys' barbels. I used to keep my corys on sand 2-3" deep and the corys did fine, but the sand caused other bacterial problems. Now I use about 1/2-1 inch depth sand or fine gravel.

I like sand when I use sponge filters or weak HOB filters that don't create strong water currents, especially with cory fry.

Cheers, Eric

[Bas Pels]

I have sand in all my tanks, and therefroe I have to take care it is not sucked into any pump

Having the suction above a flat stone, some 10 cm from its surface does help an enormous lot. I cannot say the sand causes any problems anymore

[dw1305]

Hi all,
Sand all the way for me as well.

Example: a 180 gallon tank with an FX5, sand base, and large plecos = BAD IDEA! Sand gets moved / dug up, gets sucked into filter, clogs filter, and sand destroys impeller.

You just need to put a sponge on the intake of the filter, it stops all the sand and organic waste etc. getting into the filter.

You can use a purpose made one (Eheim pre-filter part "vorfilter 4011708401910" <https://www.eheim.com/en_GB/products/ac ... _prefilter>), use a sponge block for Koi filters or you can DIY one from a sheet of PPI20 foam, details here <"http://www.planetcatfish.com/forum/view ... 3&p=249980">.

Having the suction above a flat stone, some 10 cm from its surface does help an enormous lot. I cannot say the sand causes any problems anymore

I do this as well, I also have another flat stone at the place with lowest flow, where any faeces, dead leaves etc. collects, you can syphon them out from the top of the stone.

cheers Darrel

[Supercorygirl]

I use quickrete playsand in my tanks, no issue other than a lot of rinsing needed at first. Around $10/ 50 lb bag, easy find at home depot in Canada.

[Regan]

I appreciate this excellent feedback! I have a 75 gallon tank with an Aquaclear 110 filter. 17 of my 20 cories are little juveniles. I hesitate to attach a sponge to the intake pipe on my filter to protect it from taking in sand because that burnt out an Aquaclear filter motor on me last year (instead, currently, I fashioned a fine net from a dish scrubber so the intake pipe wont kill my fishes; intake pipe killed my baby cory a couple of years ago). Crazy, it looks like ALL the sand substrates on the aquarium market are sharp and look dangerous for a cory; from what I've gathered the pool filter sand looks like the best bet for sand. My current gravel is smooth but you all got me recognizing that it is too deep, so for now at least I will remove a bunch of it so that it is not so deep they have to dig their sweet little faces into it. Thanks all!

[TwoTankAmin]

I have run prefilters on canisters and AquaClear for many years and never had this cause a problem. Prefilters require regular rinsing to prevent clogging because reduced intake flow can kill just about any filter. Reduction is always done on the output side. I use a mix of prefilters either custom made from coarse sponges (another key) and FilterMax prefilters. Never use fine pored sponge or foam on intakes as it will clog much faster.

Here is what the ATI prefilters look like:

They come with several different size and shape adapters and can be made to fit about anything. I use them on canisters, powerheads and even put one on an AC 110 on a 150 gal tank. I use sand in a few tanks and have never had an issue with it getting into any filter/intake as long as it was prefiltered.

Here is an example of a homemade sponge on an AC intake

[dw1305]

Hi all,

I appreciate this excellent feedback!.........I hesitate to attach a sponge to the intake pipe on my filter to protect it from taking in sand because that burnt out an Aquaclear filter motor on me last year....... from what I've gathered the pool filter sand looks like the best bet for sand.

I like pool filter sand.

Prefilters require regular rinsing to prevent clogging..... I use a mix of prefilters either custom made from coarse sponges (another key)

Same with me, I've never had any problem with large coarse foam (PPI10 or PPI20) filters that are regularly cleaned.

One of the reasons I like them is that you don't need to open the filter up anything like as frequently as you would without them.

cheers Darrel

[2wheelsx2]

Same with me, I've never had any problem with large coarse foam (PPI10 or PPI20) filters that are regularly cleaned.

This is the rub. I agree with what you and others have said about the pre-filters, but they just don't work people who don't work at a fixed site 24/7. For people who have to be away from home for more than 2 days at a time, any of these prefilters can be a problem. In these cases, it's easier and less worrisome to come home and clean the canister rather than deal with a clogged prefilter which has been causing the pump to cavitate for days on end. I've burnt out powerheads used to run UV's and also Eheim surface skimmers this way. And of course, even with prefilters, all filters perform better with regular maintenance anyway.

So in answer to the OP, the prefilters make sense as long as you don't have to be away from home for work or go on vacation for more than 2 weeks at a time. If you do I would not run the prefilters, and if you want to use sand, just have the intakes higher up like I do, and don't run filters like the FX5 which has the impeller at the bottom. Most canister filters have the impellers up top and won't run into a problem with sand.

With the Eheim Pro 3 style filters though, the filter hose release mechanisms are poorly designed plastic gears which can jam with a single grain of sand and I have had to replace the adapter on 2 different pro 3's for that reason so beware of that concern.

[dw1305]

Hi all,

This is the rub. I agree with what you and others have said about the pre-filters, but they just don't work people who don't work at a fixed site 24/7. For people who have to be away from home for more than 2 days at a time, any of these prefilters can be a problem. In these cases, it's easier and less worrisome to come home and clean the canister rather than deal with a clogged prefilter which has been causing the pump to cavitate for days on end.

I think if you use a big sponge block it shouldn't be a problem. I use these blocks, they sell them for Koi ponds and the largest size is 12" x 4" x 4" drilled to 11".

Some of my tanks are in the lab. and I'm often away from work (and sometimes home as well) for extended periods. The longest was 6 weeks without any maintenance, the plants were a bit overgrown, but the filter and fish were fine.



cheers Darrel

[Regan]

That looks like a good porous sponge. I often rinsed the sponge that burnt out my motor but it was just too fine of a sponge so it exhausted that motor anyway. I will look into the sponge block. Thanks Darrel