Filter Media, Plastic, Ceramic, Matrix and other

No, it is not a matter of the bigger the better, not at all. If you use too large gravel, then the surface area to volume ratio decreases and you do not want this.

The polished stones are too big and their surface area is smaller, remember if the shape it not perfectly round it is larger.

You must DEFINITELY NOT USE CRUSHER ROCK, the sort of blueish stone used for making concrete because IT IS NOT INERT, it can still release hardness into the water.

This is precisely why I recommended the crushed sandstone rock that is used for the gravel paths because it is inert and does not harden the water.

Got it?

Oh and Brent, we have a sinister tannie here on TASA and if you step out of line, just you watch it, she switches off a thread for 19 hours like nothing!

Kind regards,

Dirk

 

Oh yes, one more thing,

Oupoot that poor bloody penguin has almost drowned now, why is the other guy is still throwing him into the water again and again, shame man....

 

hahaha besides all the info this thread has given, im also having a few laughs whilst busy working Thanks for the advice prof, was just making sure about the polished rock cause it reminds me of plastic bio balls in a way...

but will i have to soak these rocks or can i just chuck them into the filter after i rinsed it a few times?

 

Yes, oupoot, the penguin must have ou pote by now as well.

You can spray this gravel strongly with a hose a couple of times and then put it into your filter.

Kind regards,

Dirk

 

Thanks for all the advice prof, i will get to the gravel once im done with the overflow pvc this weekend and also, time for the horse to do his job a bit

 

That looks like a horstrich, where did you breed that one? From a bubble mollie I am sure.

Oupoot, are you using my design for a PVC overflow?

 

Yes prof, with one modification, instead of the air pipe with the peg on to seal it, im going to use a one way air valve, what thinkness would you recommend? the 20mil or 50 mil or what size?

Thanks

 

LoL now this is a fun way to learn @oupoot love your horse, makes me tired just watching him ! Energy just like one of mine did. By the way I saw a pile of the crushed rock at a local nursery today, slightly yellowy, looks like the stuff, havent enquired if its sandstone though as I was passing by and didnt get out the car. From past experience when I had a borehole drilled, cape sandstone is common along the coast in this area so it might well be the stuff ! My filters are probably too small, but MTS is setting in here fast as I stopped keeping fish for over 20 years and had all the tanks in storage, started again about a year ago and now the third tank is out of moth balls and being prepped. Saw an awesome setup at a fish hatchery in grahamstown near here recently, especially from a filtration point of view, those stones might come in handy once its time to build a big filter to handle all the tanks..

 

Here is a link to the Table mountain sandstone common in the cape http://en.wikipedia.org/wiki/Table_Mountain_Sandstone_(Geological_Formation) not sure if this is the stuff being spoken about,

 

@brent if im not mistaken, sand stone degrades into dirt over time?

 

@oupoot I also thought so, its probably wise to make 100% sure you get the right stuff. If I am not mistaken there is a test using pool acid you can do to check if a rock is suitable to use in an aquarium. The prof would have to help us out here.

 

Sandstone will brake down as it is, as it's name suggests a sand stone. Sand stone boulders are very hard when dug out of the ground but are prone to weathering as they are sand granules held together with varying cementitious product. They are also very porous. Generally I would say thet they are not a good idea.

 

Yeah i agree, the fact that it break up means is not good

 

NO, you guys have got it wrong. Sandstone is not held together with anything looking like cement. Sandstone is HIGHLY resistant to degradation which is exactly why I have suggested that you use it. Table Mountain is made of sandstone and it is highly resistant to weathering for this very reason. This is also the reason why our water here in the Western Cape is so soft, it just simply cannot dissolve any part of the rock that it flows over. Why I am suggesting that you use these rock chips that are used for the paving is because these are made near Worcester, by a company that crushes our river stones which are made of this sandstone into small chips which can then be used for pavements and paths. If you did an acid test of this rock you would find that it does not react with acid. It will also not degrade into dirt, it just stays solid in your filter which was exactly why I told you to use this is in the first place. I am advising that you use this for these specific reasons.

Kind regards,

Dirk

 

@Dirk thanks for the explanation prof, and also for your patiens with us.... also, what thinkness of pvc pipe would you reccommend for the overflow?

 

Hi Dirk
We use the term cementitious in Geotechnical terms to describe the material bonding the individual grains together and has nothing to do with cement as you stated so you are correct and incorrect :bigsmile:. I have just completed a construction job on the side of the mountain where we had sandstone boulders from the size of your fist to the size of a car . The boulders were resistant to abrasion but not to impact. Once they were fractured or broken they wore down (the individual sand granules are hard but the cementitious/bonding material is not) which is why I said that generally it's not a good idea. I will post pics tomorrow of the type of sandstone Boulders we encountered on Table Mountain which is where I based my comment. Just wanted to clarify my statement. :blink1:

 

Hi all rather just save up for some Seachem Matrix the stuff really works, I think it is the best bio media available, here by us I pay R155 for 1 Liter of matrix and R80 for 500ml the 250ml goes for R48.

So it is really not that expensive. I will be getting another liter of the stuff for my new 650 liter tank. I already have 500ml of the stuff between my aquaclear 200 and my dolphin f-1200 internal filter.

This is just my 2 cents worth.

 

@hviviers75 I know matrix is good, but ill need about 30l worth of matrix.... and to be honest, R4650 is a bit steep and if i could i would buy it but like the prof suggested with his pebbels, we are not just looking for the best, but cheap alternitaves aswell

 

WOW!!! what size tank do you have and how many liters of water?

 

Here are 2 pics of the sandstone boulders we encountered on the side of Table Mountain. I assume the prof is not talking about these sandstone boulders and besides they won't fit in any of your tanks :bigsmile: