A pH nightmare!! any help?? please

racoll · Post by **racoll** » 16 Jul 2004, 18:21

hello, having recently set up my 5 foot show tank and looking foward to collecting some interesting loricariids and cichlids i am suffering from problems with pH.

i have an RO of which i mix with tap water at a ratio of 2:1. tap water is at a pH of 7.5 and the RO water a pH of 6.5. i change 25% weekly.

the tank has a dHÂ° of 5.6 and a KH of 70 mg/l, but a pH of 8.3!
it is filled to the brim with bogwood.

the sand and the rocks were both sold to me at the lfs, and i was assured that they were both lime free.

i did some tests of both in neat RO water.

after about a week....

sand: raised dHÂ° to 3.36. KH to 50 mg/l but the pH to 7.87

rocks (rounded sedimentary) raised dHÂ° to 2.24. KH to 30 mg/l but the pH to 8.2.

i took the rocks out and changed the water. nothing.
i put half a litre of peat in a bag and attached it to the spraybar. nothing.

what is causing my pH to keep going so high??

i will take the sand out only as a last resort.

i have just bought an eheim 2213 which i intend to fill with peat (will this be enough?). as aquarium peat is so expensive is there a viable alternative?? organic peat with no added chemicals from the garden centre? or will this cloud (not discolour with tannins) the water?

sorry about all the data and questions, but i think it's necessary to work out what's going on.
thanks for any help.

ps. i have a digital pH meter which i calibrated a couple of weeks ago.

racoll · Post by **racoll** » 16 Jul 2004, 18:40

after browsing through some of the posts i noticed that heavy aeration may be the cause (i had my suspicions). i have a large airstone that hits the surface under two powerfilter spraybars that are out of the water.

well if this the case this brings me onto how i can provide enough oxygen for the loricariids i aim to keep:

Leporancathicus triactis
L102 snowballs
nuggets
Sturisoma panamense

(although probably not all the above)

Post by **Barbie** » 17 Jul 2004, 04:45

if your carbonate hardness is rising after you add water to the tank, it's coming from something in the tank, period. The kH is the ability of the water to hold a stable pH, basically. To test your sand, take out a cup full and pour in vinegar. If it bubbles, that is the culprit. Aeration can definitely be causing a rise in pH if your tap water is coming out saturated in CO2, or at least low in dissolved oxygen. Try aerating tap water over night and it might give you an idea of where it finds it's balance point also. You may just need to initially push the pH down with a small amount of some form of acid buffer, but make sure you keep your kH high enough to maintain a stable pH, when you find the level you want. I would definitely not sacrifice the oxygenation. You may just need more RO to the tap water ratio. Do you know the kH of your tap water?

Barbie

racoll · Post by **racoll** » 17 Jul 2004, 13:41

thanks for your help barbie.

before i read your post i turned off the air-pump and took off the spray-bars last night and sure enough the pH slowly dropped to 7.8. unfortunatly my tetras were gasping for oxygen. so the air-pump is back on.

what can i do? i don't trust using acid buffers or any other product like that in my tanks. any guidance on which ones are the best and how to use them? i'd rather use peat (see my peat questions above).

my tests i carried out in mugs indicated that there was a residue of carbonates in the sand, as it put the KH up, but the pH only went up to 7.87 (see results in above post) and not to 8.3 (which is where the tank was stable.

my tap water KH is 180mg/l

i wish i wanted to keep tanganikans. it would be so easy then!! well i do, but..... i can't afford another tank at present!!

stop press... i just covered some sand in vinegar and there are some (very few) white grains just a tiny bit larger than the sand that are releasing streams of bubbles. i had my suspicions, but i didn't realise that such tiny amounts could raise the KH so high. so i presume this coupled with heavy aeration is driving the pH up.

i don't know if i'm more angry with my self for taking the LFS's word that it was lime free, or with them for being so negligent.

now i will have to sieve the sand or find a source that i can trust. ideas?

Post by **Barbie** » 17 Jul 2004, 17:34

I wouldn't recommend adding ANY acid buffer or the like to your tank. You should have a garbage can full of water that is "aging" to be used in your tank. It works pretty well and with just a powerhead and small heater running in it, it keeps it in great shape to be used immediately that way.

Since your sand is adding buffering capacity, you can probably get away with a much smaller portion of tap water to your RO water before addition to your tank. I would personally probably remove that sand and take it back and offer to show the owner of the store just why it is NOT suitable for your uses. Preferably on a busy saturday afternoon with a store full of customers, but I'm just a wee bit evil that way

You can now offer to test any sand that you are interested in purchasing before you take it home, so that should help at least.

Go ahead and test the pH of the tap water after aeration also. That might also be affecting your end result.

Barbie

magnum4 · Post by **magnum4** » 17 Jul 2004, 19:39

i don't know if i'm more angry with my self for taking the LFS's word that it was lime free, or with them for being so negligent.

slightly off topic but: is it alwas an LFS fault if the product is faulty? isn't it the manufactures fault for selling it to the LFS as lime free gravel?

Look out for BD trading sand by far the best sand for any tank.

racoll · Post by **racoll** » 24 Jul 2004, 13:30

magnum4:

i think that if a retailer is selling a product for a specialist use then they should go as far as is reasonable to make sure the product is fit for that use. now i consider it reasonable to test their "lime free" sand for lime! but you are right, the manufacturer should do the same.

Barbie,

i shall test the pH of the aerated tap water when i get a new another pump (the fish need them at the moment- it's quite hot here). well for england!!

so if i treat the RO with a brand of aquarium acid and add it it to the tank gradually as part of the water changes, you think the the pH will slowly fall because the acid can't be driven out of solution by aeration like carbonic acid can?

i'd rather use peat though. will an eheim 2213 full of it be enough to acheive results?

and sorry to ask the same question again but is there a safe cheaper alternative to aquarium peat that costs Â£5 for a small box?

thanks for your help.

Post by **Rusty** » 24 Jul 2004, 15:16

You can use boiled oak leaves on top of your substrate, which will slowly lower the pH. If you do a search on the topic, there are several threads discussing this.

Rusty

racoll · Post by **racoll** » 24 Jul 2004, 15:28

i tried some beech leaves in a mug of tap water (very hard) and nothing happened. i will try it again though as my tank water is a lot softer now due to the RO.

ta