The Puffer Forum

What are good water numbers for a new brackish tank?

I've seen recommendations of pH between 7-8.5 - but what about kh and gh? Does that still apply to brackish?

I've got the salinity thing down - right now the LFS has the F8 in almost FW so I am seting up to match as not to shock the F8 (its 1.004 if I am writing it correctly). My thought would be to increase it over time to a true light brackish. But do it very slowly with the weekly water changes.

Brackish tanks are IMHO & IME better at higher pH - which is why I use aragonite substrates for such (especially imortant in light or low-density BW). The slightly soluble substrate boosts the KH and GH of the water somewhat more than the low levels of marine mix does. BW fish are quite adaptable to TDS (total dissolved solids) and variations in pH/GH/KH in the wild, but for me, the captive fish are better with higher and more stable pH/GH/KH.

To me at least, 1.004 is a light BW. Below 1.003 there may be issues with KH and pH decline between water changes with messy fish such as puffers unless buffering substrates are used. F-8s are not demanding, I think 1.005 is a good level for them, up to 1.008. If i did not have a buffering substrate in their tank, I would likely tend to use the higher part of that range. With a buffering substrate, 1.004-5 specific gravity would be fine to me.

PH should remain steady, right around 8. Best done by using crushed coral or aragonite, as substrate.

So I should go with whatever kh/gh levels maintain a stable pH in the tank?

My tap water is horrid - I have ZERO kh or gh and my pH is so low it won't register on the test kit. I've been adding Kent R/O Right to boost the gh of my fresh water tank and baking soda to boost the kh (I couldn't get it to cycle until I fixed the gh/kh levels). I've gotten really good at keeping those numbers consistent with that combo of addititives.

I already have the tank set up and running with very very small aquarium gravel - I can't find the sand anywhere around here. Home Depot didn't have it and none of hte LFS have actual sand - just gravel. I did add some real shells to the tank - and I am using a homemade cave system made out of terracotta flower pots (glued w/silicon) and plastic plants.

Right now the gh in the tank is about 100 (API drop test kit) but the ph and kh are non-existent due to my crummy tap water. Should I go ahead and boost it with the baking soda or use something else? I added some Instant Ocean to add the minor salinity -its at 1.004 which is exactly what the LFS has the F8's in right now.

Using aragonite and/or crushed coral would be a good idea in your situation to help maintain proper levels. You can find it online at a place like big als. It would be worthwhile picking some up.

Before trying to adjust your kH or pH try aerating your water for 24 hours. Simply put some tap water in a 5 gallon bucket with a power head in it and let it run for 24 hours. Then do your tests....

Or aerate with an aerator and airstone for 24 hours - then check.

With extremely soft (no GH) and unbuffered/no alkalinity (no KH), aeration won't read significantly different from what she sees now. That just gets rid of elevated CO2 from pressurization and allows short acting phosphate buffers added by the utility(if any) to break down.

In your situation, I would definitely use aragoniite. I would likely adjust the KH up with bicarb before adding the marine mix as well. The bicarb will be a short-term fix, the substrate and marine mix longer-term.

I'm having a "duh" moment- refresh my memory please - the aragoniite is the sand that will react with vinegar?

Home depot had two types of sand - I will ask if I can pinch a bit from the broken bags and test.

Home Depot will not have aragonite sand. You must buy that from a aquarium supply store.

Actually, some ACE, Home Depots and other hardware sores do carry a white Caribbean aragonite play sand marketed for use in sand boxes. It is usually bagged under the names Yard Right, White Castle or Southdown.

I've never heard of HD refusing to sell anything. A quick 1-800 call to corporate would resolve that problem in no time!

Note: Even if the bags are marked with the brand names mentioned above, you still need to test to determine if it is aragonite or not.

I've never had HD refuse to sell me anything- besides - what business it of theirs what I am using it for?? anywho....

So just to clarify- the sand I want will be the one that foams up with the vinegar test?

WoOt! I just noticed your signature. Boxer luvin is the best, eh? Nothing beats coming home to the beans!

I've never heard of aragonite reacting with vinegar. is that true?