Substrate advice

[Irkrts]

Hello everyone! Thanks for all your advice.

I'm viewing a large 250-300L aquarium this weekend, and am planning to keep a mix of tropical fish in it. My goal is to have a well planted tank with several rocks and white sand, similar to how cichlid tanks often are, although with plants too.

All the substrates I read for sale advertise that they raise the pH, thus making them ideal for cichlids.

Will this be compatible with healthy mixed tropical inhabitants? It will mostly be rearranged fish from my other tanks, so tetras, corys, maybe loaches. Are there any species that are very intolerant of this substrate and the raised pH?

Thank you very much!

 

[Essjay]

There are broadly two types of cichlid - those that need soft water and those that need hard water. Hard water cichlids are not compatible with soft water fish such as cories, loaches and tetras. And any substrate that raises pH will also make the water harder, which is not suitable for soft water fish.

White sand is not a good colour as virtually all fish have evolved over darker substrates. White sand stresses fish. Buff or grey sand is better for fish, and they tend to be inert so won't increase GH or pH for the soft water fish.

 

[Jan Cavalieri]

That really depends on how high your PH is going to get. I'd say most tropical freshwater fish prefer PH's in the range of 6.8 to 8 range, some require as low as 5-6 but that is rare. Some it's 6.8-7.2 which is where I prefer to keep all my tanks. There are a number of websites including Wikipedia that will tell you the exact parameters a particular species requires. The online seller LiveAquaria also lists the parameters their fish require. I'm sure other online sellers do as well.

Personally I wouldn't mix any other fish with cichlids and only get the semi-aggressive cichlids rather than include some of the few peaceful varieties or any of the aggressive varieties.. Expect a lot of aggression but unless they are rated "aggressive" instead of semi-aggressive I wouldn't have them. Also keep all long finned fish away from them even if they are also cichlids unless you want to see some deaths and fin-nipping

I would never add a tetra or loach to a cichlid tank - My cory's all tend to get left alone but I wouldn't count on it.

Anyway - I'd be FAR less concerned about the PH than I would be concerned about mixing peaceful and aggressive fish together. I do have one cichlid that a lying store owner sold me as a gourami - and, in fact, a number of the larger gouramis (but not all) are also semi-aggressive - I have her in a tank with those Gourami's - she gets alternatively ignored and picked on by the Gourami's - nothing more than chasing and body slamming - no fin nipping but these are all short finned fish for that reason. She can hold her own just fine but I think she's lonely for her own kind.

Now if you are NOT getting any cichlids - I would avoid any PH raising substrate - I didn't even know such a thing existed and wouldn't put it in my tanks. I also am not a fan of white substrate just because it shows the grime too well, plus non-cichlids fish aren't always as brightly colored as cichlids - so you might consider getting black substrate where they will show up better. I use Seachem's fluorite - either the black clay substrate or the black sand.or both (skip the "dark" - it's actually an ugly medium brown which I bought by mistake. All of their substrates take a lot of rinsing before using in a tank (I use a fine mesh colander and wash at least 4 times) but it's the best of the best in substrates. Some species in the loaches and plecos groups like to bury themselves - so sand in at least one part of the aquarium is good. The clay in general is softer than the hard cutting gravel found in other cheaper substrates so it's less hard on the Cory's faces.

I always have at least 3" of substrate if I am adding live plants - it makes them so much easier to plant.

You also should test the PH of your tap water if that's what you are going to use. My city's avg PH is 9.4 so every time I do a major water change I have to fight having PH's in the 8.9 range (as high as my kit will go) then I fight with PH down - because depending on your water hardness you may set your water to a particular PH but find that it will continue to decrease over time - until it's too low for the fish. Then I have to use a bit of PHup to get it back to around 7 - then it seems to hold steady fairly well until the next water change (I change mine once a week so that's a lot of messing with PH). PH changes are hard on fish so they have to be done slowly and carefully, but I couldn't have any fish if I didn't work on adjusting the pH every week. It is very frustrating.

 

[Irkrts]

Essjay and Jan - thanks very much.
Yes should clarify - I do not intend to mix cichlids and mixed tropicals, but only to keep mixed tropicals.

The kind of sand / gravel I am looking at now- many of them state "natural pH that will not alter your water chemistry" - does this mean I don't need to worry about the water parameters being different from my current aquarium (which is small rounded pebbles), were I to buy any of these?

Thank you!

 

[Essjay]

Yes, if the packaging says it won't alter the water chemistry, it won't change pH or GH. The substrates that increase pH and GH are usually used for tanks with Rift Lake cichlids which need very hard water with high pH.

If you intend cories or loaches, get sand. It is much better for them than gravel. Cories take mouthfuls of sand, sift it for morsels of food, then expel the sand through their gills. They cannot do this with gravel.
Play sand is the cheapest and it is safe as children will eat it, intentionally or unintentionally. However, I don't know where you live and an Australian member has said that there, play sand can be coarse, but if you are in the UK, USA or Canada, play sand is perfect.

 

[Byron]

I agree with what essjay has posted, but to turn the discussion in a bit of a different direction...the first thing to decide is exactly what fish species you intend keeping in this tank. If for example Corydoras catfish are intended as one of the species, you basically need sand. If on the other hand your intention is to replicate a Central American stream which would mean livebearers (and no cories), gravel will be authentic (or still sand).

As far as plants go, they will thrive in almost any substrate, including inert sand and fine gravel. There is no need for "plant" enriched substrates that may impact GH/KH/pH. For years I had fine gravel, then I changed over to play sand some 7 years ago, and all my tanks are planted. It is best to avoid any substrate that will impact parameters, simply because there is less effect on water chemistry and this means less chance for trouble. Having said that, in a tank intended to house only harder water fish, a calcareous substrate (one that slowly dissolves calcium and magnesium into the water, raising GH/KH/pH) will not harm and may benefit.

Another thing we need to know is the GH, KH and pH of your source water. This data you may be able to get from the water authority, check their website. When we know this data, along with the intended fish species, we will be able to advise more.

 

[PheonixKingZ]

If you really want to have white sand, then go for it. But...i don’t recommend it. White sand can be stressful for fish, as well as look messy at times.