spinnerbayt

I have a 125 gal. tank and normal aquarium gravel that is I would say is of medium size. I know this isn't the best for plants so my question is if I break down the tank and mix the bottom half with sand and laterite will this work alright or what should I do? I just hate to replace my whole substrate cause that would be quite costly. Any help would be great!

MatPat

When I first converted my 75g to a planted tank, I had the larger type gravel also. I followed some recommendations to add some laterite to my tank and it was a disaster! The water was continuously cloudy for almost two months!
I finally gave up the laterite idea and switched out the substrate to Eco Complete and Tahitian Moon sand.

If you want to add the laterite, I would suggest you add a good amount of sand to your tank to keep the laterite from leeching up into the water column. It is very unsightly to have an orange cloud in your tank all of the time, trust me

You may want to check into some Schultz Aquatic Plant Soil (SAPS). It is a brownish red color that looks pretty good once it is in the tank. It is light weight, so you may want to mix this with some sand also. It can be found at Wal Mart and I'm sure some other places that cater to the pond crowd. It is fairly cheap if you can find the 20lb bags. It has a decent iron content (can be used to replace the laterite) and an excellent CEC. You should be able to find silica sand at a better LFS for pretty cheap also.

I have read that play sand is a bit too fine but have used it in the past (mixed with SAPS) without a problem. Some say it tends to compact after it has been in the tank for a while.

Hope this helps

trenac

Depending on the color gravel you have now I would add either Flourite or Eco-complete to what is already in the tank to make a depth of 2-3 inches. Remember that the smaller gravel will end up underneath the larger gravel as the gravel gets stirred up during water changes.

Raul-7

I don't think Profile/SAPS is the best choice. Although it has a faily high CEC and good FE/trace content, the nutrients are seemingly unavailble to the plants. I've read many posts on the APD confirming this and Tom does too. It is at best used for it's CEC ability. I'd recommend you use Flourite(red) or Eco Complete(black), you can use a 50:50 mix of Flourite:Gravel if you want to save money.

jppurchase

Hogwash!

its the CEC level of a substrate which attracts and holds nutrients in the substrate, ready to be absorbed by the plant roots. The only major fault I can find with Profile, and its a major one, is that it is too light weight. Some plants have difficulty staying planted in the stuff and too much current can move it around.

James Purchase
Toronto

MatPat

I agree with jppurchase. I have used SAPS in the past with pretty good results! Even if the nutrients are "seemingly unavailable" to the plants, they grew very well! Maybe this has more to do with the fact that I kept the water column very well dosed and did not rely on the substrate.

My P. stellata in this tank had stalks the size of a normal man's finger so I'm not complaining. The L. sp 'Cuba' also grew similar size stalks so something must have been good. I found a source for Turface at $9.99 for 50lbs so the price is definately worth another experiment. I will mix it with some sand to give it some "weight" though.

As far as nutrients in the substrate being available to the plants, I have a low light tank (15w on 10g) with crypts, anubias, Elatine tiandra, Pearlweed, Java Ferns, and Dwarf Sag. The substrate is 100% Tahitian Moon Sand with no fert tabs and everything is growing well. It has only been about 3 months now so time will tell....

owengibson

Do youhave a 400W Metal halide on the tank? If so, plant some hardy tall plants like swords and vals and hairgrass and Im sure their roots will be just fine in normal aquarium gravel. If the plants are going to get really big, have a really deep substrate for the roots... add some different sized gravel and some laterite or one of them fancy brands. I will be an awesome tank!

Aquarium gravel is FINE! Mix the laterite in slowly and wash it really good to avoid a red tank!