Can I Use Slate As A Substrate?

[IAmATeaf]

Can I use slate as a substrate in a freshwater aquarium? I've done lots of googling and get conflicting hits coming back, some say yes and others say no-way so I'm confused. The slate I have are chunks that range from 2cm to 5cm and where being used in an aquarium before.

 

[waterdrop]

Hi there and Welcome to our beginners section,

Slate and Flagstone used to be widely used as the bottom plate in aquarium construction, back in the old days of high quality ( ) and the materials are totally safe for freshwater use as far as I know. They don't raise mineral hardness or pH as some rocks do. They are often used as decorative rocks and for construction of caves for cichlids I also believe. So yes, they are fine as decorative additions to a tank.

There are a couple of things to think about though. If you are considering slate that's all crushed up to make a general substrate, you might find that to be way too sharp edged for your fish and especially any bottom dwellers. If you are considering a huge stack of slate to make caves or such then you need to be quite careful, considering whether any part could collapse and crush your fish. We sometimes see beginners building stacks like this and not considering how things can shift without notice over time. When one is doing maintenance with a gravel cleaner or even just a siphon tube, the rock constructions can be nudged and caused to become less stable, possibly unnoticed by you.

I also am unsure about the weight of a larger stack of rock like slate. Water is quite heavy and tanks are build to handle plenty of even weight, even with normal glass bottoms, but of course rock is denser and heavier and I've always wondered if you could reach a point where a stack of rock exerting uneven pressure at some point on the bottom glass would crack it. Perhaps some of the members with experience in this could comment.

~~waterdrop~~

 

[VaegaVic]

I would also possibly consider, just to add to Waterdrop's post, the maintenance of such a substrate. You'd have dirt hidden all over the place, causing you to gravel clean more often, which means larger water changes, which means more stress for the fish.

It would look rather nice if done right though.

 

[IAmATeaf]

So how or what would be the easiest way of cleaning an all slate substrate then? Would a normal syphon cleaning thingy be up to the job?

 

[VaegaVic]

So how or what would be the easiest way of cleaning an all slate substrate then? Would a normal syphon cleaning thingy be up to the job?

Well this is the thing.
The larger the particles of substrate, the harder it is to clean generally. Reason being is that there are more places for dirt to hide, hence why sand is the easiest to keep clean.

I'm sure you could use a gravel cleaner, but you'll really have to disturb the slate every single time you clean, which in itself, can be dangerous for fish.

 

[IAmATeaf]

Think I'll try it provided it's safe for the fish, can always get rid of it if it causes me real problems.

 

[IAmATeaf]

Right, I've cleaned my tank and the slate chips, put the chips into the tanks and filled the tank up with around 2" of water but whilst filling up I noticed bubbles clumping together, very much like washing up liquid bubbles but not as shiney or as white, the bubbles looked very chalky/off white if that makes sense.

So I stopped filling that tanks last night to see what happens to the bubbles in the morning and some are still there.

Now onto the admission side of things The tank was very dirty so I scrubbed it using a scourer and a tiny drop of washing up liquid. I didn't rinse the tank after doing this as it's bloody huge so wiped it over with with a flannel 3-4 times rinsing the flannel in clean water whenever I'd wiped about 12" of glass.

This may be a stupid question but is it likely that the bubbles are left over bits of washing up liquid? I've resigned myself to the fact that I'm going to have to empty the tank, take it into the garden and give it a good hose down but am wondering what else may be causing these bubbles.

EDIT: Another question, I'll be clcling the water for some days so if there were traces of washing liquid in the water then would the filter eventually remove it?

 

[waterdrop]

Soaps and detergents are quite dangerous to fish, so the rinse out process to remove all traces of this should be thorough. Tap water is under pressure inside the pipes. The extra pressure allows it to retain a higher amount of CO2 dissolved. When you fill a tank you will nearly always see a lot of small bubbles associated with this excess CO2 now gassing out due to the lower pressure of being out of the pipes.

~~waterdrop~~

 

[IAmATeaf]

Soaps and detergents are quite dangerous to fish, so the rinse out process to remove all traces of this should be thorough. Tap water is under pressure inside the pipes. The extra pressure allows it to retain a higher amount of CO2 dissolved. When you fill a tank you will nearly always see a lot of small bubbles associated with this excess CO2 now gassing out due to the lower pressure of being out of the pipes.

~~waterdrop~~

I cleaned the tank again on Saturday, cleaned the substrate again, then filled it with around 2" of water, water was clean with only air bubbles. Then started adding the slate substrate and the milky bubbles started appearing again so it looks like it must have been the substrate all along. So I took out as many of the bubbles I could and then continued to fill the tank all the way to the top and then did another mop up of the bubbles. Started my Fluval 305 filter and let that run all weekend and the water is now cystal clear.

One thing that I have noticed is that if I move the filter from side to side or back to front I get a load of air coming out. Did this a few times and thought all the airs gone but did the same a few hours later and more and again the same a few hours later. I've checked all the seals and no leaks, both the inlet and outlet ends at the tank where the pipe connects are under around 1" of water so an wondering where the air might be coming from. Could there really be that much air trapped in the filter?

 

[waterdrop]

Yes, that is normal after starting up an external cannister filter. Lots and lots of air bubbles are trapped in the media. They come up and collect in the domed path to the pumphead and periodically come out in a shower. I usually give a newly filled cannister filter a slight tilt and minor shake every now and then.. but not too much as you don't want enough air to come out at once that it will leave the impeller without water. By now you've probably found it settled down.

~~waterdrop~~

 

[IAmATeaf]

Yes, that is normal after starting up an external cannister filter. Lots and lots of air bubbles are trapped in the media. They come up and collect in the domed path to the pumphead and periodically come out in a shower. I usually give a newly filled cannister filter a slight tilt and minor shake every now and then.. but not too much as you don't want enough air to come out at once that it will leave the impeller without water. By now you've probably found it settled down.

~~waterdrop~~

Ah so the air is trapped in the media which explains why I get more air out after a few hours.

Also is it normal to have a phobia about the external filter leaking I've placed it in a bucket in the cabinet and find that I keep going back to it every few hours to check that it's not started leaking. Saturday evening I woke up in the middle of the night with a need to go down and check the damned thing

The bucket does have a disadvantage though, it seems to amplify the noise of the filter which with my open backed cabinet can be heard as gentle hum.

 

[waterdrop]

Personally I think an extra catch is a very sensible thing. I wrote down dimensions of my cabinet and cannister filter and went to a bigbox store. After a lot of searching I found one of those square/rectangular clearish plastic (rubbermaid is one of the brands) storage boxes used for kitchen and other storage. Its low enough that I wouldn't think it would effect your sound (mine is so quiet you can't detect its on!) But it could catch quite a bit of water if the cannister leaked.

A good cannister filter that is carefully maintained should never leak though. Each time you perform your monthly (or whatever interval you settle on) cleaning you should also perform impeller and seal maintenance. The seal maintenance consists of rubbing down all of the silicone seals with a lubricant. There are perfect silicone lubricants for this but its my opinion that vasoline can be used safely in a pinch. The seal for the main body can just stay in place but you run the lubricant all around it with your fingers. Don't be afraid to be messy - you can wipe off some of the excess with a towel. What this maintenance does is keep the silicone from oxidizing over time and eventually cracking.

~~waterdrop~~

 

[IAmATeaf]

Thanks for the info, much appreciated.

I did do a lot of reading here and coated the rubber seals with vasoline but forgot all about the impeller shaft. Might take the thing apart this weekend and do that, might quieten the thing down a bit too.

 

[waterdrop]

I don't know how it varies for the other cannister makers but for my Eheim I was able to get a nice little brush kit with several brushes that perfectly fit various cavities when I'm cleaning the impeller and surrounding areas. Impeller maintenance should always be undertaken with attention and care. Most impeller shafts these days are made of ceramic and can break easily. On most, once you've removed the top to release the top of the shaft you can lift the entire impeller and rotor magnet, gently sliding it off the ceramic shaft. Gently clean the shaft and set it somewhere it can't roll. Use brushes to clean the impeller blades, magnet and the cavity you removed them from. Reassemble. Use brushes to clean any other passageways in the pumphead that you can reach.

~~waterdrop~~